TY  - GEN
A1  - Püschel, Gerhard Paul
A1  - Mentlein, Rolf
A1  - Heymann, Eberhard
T1  - Isolation and characterization of Dipeptidyl Peptidase IV from human placenta
N2  - Human placenta is surprisingly rich in post-proline dipeptidyl peptidase activity. Among various cell fractions, microsomes have the highest specific activity. A homogeneous enzyme preparation is obtained in a six-step purification procedure. The final preparation appears homogeneous upon dodecyl sulfate electrophoresis, but analytical isoelectric focussing reveals various active bands with isoelectric points in the range of pH 3 - 4. The enzyme is a glycoprotein containing about 30% carbohydrate. Treatment with neuraminidase lowers the isoelectric points but does not reduce the heterogeneity of the band pattern. The subunit molecular weight is 120000 as estimated by dodecyl sulfate electrophoresis, whereas Mr of the native enzyme is > 200000, as can be concluded from gel filtration experiments. The purified dipeptidyl peptidase cleaves various synthetic and natural peptides, including substance P, kentsin, casomorphin and a synthetic renin inhibitor. In general, the specificity of the placenta peptidase is similar to that of post-proline dipeptidyl peptidase from other sources. Phenylalanylprolyl-P-naphthylamide (Km = 0.02 mM, I/ = 92 Ujmg) is the best substrate among various synthetic peptide derivatives. Only peptides with a free N-terminal amino group and proline, hydroxyproline, or alanine in position 2 of the N-terminal sequence are cieaved. However, X-Pro-Pro- . . . structures, e. g. as in bradykinin, are not attacked. 1 mM bis-(6nitrophenyI)phosphate or 1 mM diisopropylfluorophosphate completely inactivate the peptidase within 30 min at 30°C (pH 8). The peptidase is also completely inhibited by 1 mM Zn²⁺ and by other heavy metals.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 114 
Y1  - 1982
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45875
ER  - 
TY  - GEN
A1  - Püschel, Gerhard Paul
A1  - Nath, Annegret
A1  - Jungermann, Kurt
T1  - Increase of urate formation by stimulation of sympathetic hepatic nerves, circulating noradrenaline and glucagon inthe perfused rat liver
N2  - In the isolated rat liver perfused in situ stimulation of the nerve bundles around the portal vein and the hepatic artery caused an increase of urate formation that was inhibited by the α1-blocker prazosine and the xanthine oxidase inhibitor allopurinol. Moreover, nerve stimulation increased glucose and lactate output and decreased perfusion flow. Infusion of noradrenaline had similar effects. Compared to nerve stimulation infusion of glucagon led to a less pronounced increase of urate formation and a twice as large increase in glucose output but a decrease in lactate release without affecting the flow rate. Insulin had no effect on any of the parameters studied.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 038 
KW  - Urate
KW  - Allantoin
KW  - Hepatic nerve
KW  - Catecholamine
KW  - Glucagon
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16728
ER  - 
TY  - GEN
A1  - Püschel, Gerhard Paul
A1  - Jungermann, Kurt
T1  - Activation of inositol phosphate formation by circulating noradrenaline but not by sympathetic nerve stimulation with a similar increase of glucose release in perfused rat liver
N2  - In the isolated rat liver perfused in situ, stimulation of the nerve bundles around the hepatic artery and portal vein caused an increase of glucose and lactate output and a reduction of perfusion flow. These changes could be inhibited completely by α-receptor blockers. The possible involvement of inositol phosphates in the intracellular signal transmission was studied. 1. In cell-suspension experiments, which were performed as a positive control, noradrenaline caused an increase in glucose output and, in the presence of 10 mM LiCl, a dose-dependent and time-dependent increase of inositol mono, bis and trisphosphate. 2. In the perfused rat liver 1 μM noradrenaline caused an increase of glucose and lactate output and in the presence of 10 mM LiCl a time-dependent increase of inositol mono, bis and trisphosphate that was comparable to that observed in cell suspensions. 3. In the perfused rat liver stimulation of the nerve bundles around the portal vein and hepatic artery caused a similar increase in glucose and lactate output to that produced by noradrenaline, but in the presence of 10 mM LiCl there was a smaller increase of inositol monophosphate and no increase of inositol bis and trisphosphate. These findings are in line with the proposal that circulating noradrenaline reaches every hepatocyte, causing a clear overall increase of inositol phosphate formation and thus calcium release from the endoplasmic reticulum, while the hepatic nerves reach only a few cells causing there a small local change of inositol phosphate metabolism and thence a propagation of the signal via gap junctions.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 110 
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45846
ER  - 
TY  - GEN
A1  - Püschel, Gerhard Paul
A1  - Oppermann, Martin
A1  - Muschol, Waldemar
A1  - Götze, Otto
A1  - Jungermann, Kurt
T1  - Increase of glucose and lactate output and decrease of flow by human anaphylatoxin C3a but not C5a in perfused rat liver
N2  - The complement fragments C3a and C5a were purified from zymosan-activated human serum by column chromatographic procedures after the bulk of the proteins had been removed by acidic polyethylene glycol precipitation. In the isolated in situ perfused rat liver C3a increased glucose and lactate output and reduced flow. Its effects were enhanced in the presence of the carboxypeptidase inhibitor DL-mercaptomethyl-3-guanidinoethylthio-propanoic acid (MERGETPA) and abolished by preincubation of the anaphylatoxin with carboxypeptidase B or with Fab fragments of an anti-C3a monoclonal antibody. The C3a effects were partially inhibited by the thromboxane antagonist BM13505. C5a had no effect. It is concluded that locally but not systemically produced C3a may play an important role in the regulation of local metabolism and hemodynamics during inflammatory processes in the liver.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 039 
KW  - Hepatic glucose balance
KW  - Hepatic lactate balance
KW  - Hepatic hemodynamics
KW  - Complement system
KW  - Anaphylatoxin
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16733
ER  - 
TY  - GEN
A1  - Püschel, Gerhard Paul
A1  - Oppermann, Martin
A1  - Neuschäfer-Rube, Frank
A1  - Götze, Otto
A1  - Jungermann, Kurt
T1  - Differential effects of human anaphylatoxin C3a on glucose output and flow in rat liver during orthograde and retrograde perfusion : the periportal scavenger cell hypothesis
N2  - 1) During orthograde perfusion of rat liver human anaphylatoxin C3a caused an increase in glucose and lactate output and reduction of flow. These effects could be enhanced nearly twofold by co-infusion of the carboxypeptidase inhibitor MERGETPA, which reduced inactivation of C3a to C3adesArg. 2) During retrograde perfusion C3a caused a two- to threefold larger increase in glucose and lactate output and reduction of flow than in orthograde perfusions. These actions tended to be slightly enhanced by MERGETPA. 3) The elimination of C3a plus C3adesArg immunoreactivity during a single liver passage was around 67%, irrespective of the perfusion direction and the presence of the carboxypeptidase inhibitor MERGETPA; however, less C3adesArg and more intact C3a appeared in the perfusate in the presence of MERGETPA in orthograde and retrogade perfusions It is concluded that rat liver inactivated human anaphylatoxin C3a by conversion to C3adesArg and moreover eliminated it by an additional process. The inactivation to C3adesArg seemed to be located predominantly in the proximal periportal region of the liver sinusoid, since C3a was less effective in orthograde perfusions, when C3a first passed the proximal periportal region before reaching the predominant mass of parenchyma as its site of action, than in retrograde perfusions, when it first passed the perivenous area. These data may be evidence for a periportal scavenger mechanism, by which the liver protects itself from systemically released mediators of inflammation that interfere with the local regulation of liver metabolism and hemodynamics.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 040 
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16747
ER  - 
TY  - GEN
A1  - Muschol, Waldemar
A1  - Püschel, Gerhard Paul
A1  - Hülsmann, Martina
A1  - Jungermann, Kurt
T1  - Eicosanoid-mediated increase in glucose and lactate output as well as decrease and redistribution of flow by complement-activated rat serum in perfused rat liver
N2  - Rat serum, in which the complement sytem had been activated by incubation with zymosan, increased the glucose and lactate output, and reduced and redistributed the flow in isolated perfused rat liver clearly more than the control serum. Heat inactivation of the rat serum prior to zymosan incubation abolished this difference. Metabolic and hemodynamic alterations caused by the activated serum were dose dependent. They were almost completely inhibited by the cyclooxygenase inhibitor indomethacin and by the thromboxane antagonist 4-[2-(4-chlorobenzenesulfonamide)-ethyl]-benzene-acetica cid (BM 13505), but clearly less efficiently by the 5’-lipoxygenase inhibitor nordihydroguaiaretic acid and the leukotriene antagonist N-{3-[3-(4-acetyl-3-hydroxy-2-propyl-phenoxy)-propoxy]-4-chlorine-6-methyl-phenyl}-1H-tetrazole-5-carboxamide sodium salt (CGP 35949 B). Control serum and to a much larger extent complement-activated serum, caused an overflow of thromboxane B₂ and prostaglandin F₂α into the hepatic vein. It is concluded that the activated complement system of rat serum can influence liver metabolism and hemodynamics via release from nonparenchymal liver cells of thromboxane and prostaglandins, the latter of which can in turn act on the parenchymal cells.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - pape 116 
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45892
ER  - 
TY  - GEN
A1  - Gardemann, Andreas
A1  - Püschel, Gerhard Paul
A1  - Jungermann, Kurt
T1  - Nervous control of liver metabolism and hemodynamics
N2  - Content: Anatomy of hepatic innervation In vivo studies on the role of hepatic nerves Effects of hepatic nerves in isolated perfused liver Mechanism of action of sympathetic hepatic nerves
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 164 
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-51346
ER  - 
TY  - GEN
A1  - Püschel, Gerhard Paul
A1  - Hespeling, Ursula
A1  - Oppermann, Martin
A1  - Dieter, Peter
T1  - Increase in prostanoid formation in rat liver macrophages (Kupffer cells) by human anaphylatoxin C3a
N2  - Human anaphylatoxin C3a increases glycogenolysis in perfused rat liver. This action is inhibited by prostanoid synthesis inhibitors and prostanoid antagonists. Because prostanoids but not anaphylatoxin C3a can increase glycogenolysis in hepatocytes, it has been proposed that prostanoid formation in nonparenchymal cells represents an important step in the C3a-dependent increase in hepatic glycogenolysis. This study shows that (a) human anaphylatoxin C3a (0.1 to 10 mug/ml) dose-dependently increased prostaglandin D2, thromboxane B, and prostaglandin F2alpha formation in rat liver macrophages (Kupffer cells); (b) the C3a-mediated increase in prostanoid formation was maximal after 2 min and showed tachyphylaxis; and (c) the C3a-elicited prostanoid formation could be inhibited specifically by preincubation of C3a with carboxypeptidase B to remove the essential C-terminal arginine or by preincubation of C3a with Fab fragments of a neutralizing monoclonal antibody. These data support the hypothesis that the C3a-dependent activation of hepatic glycogenolysis is mediated by way of a C3a-induced prostanoid production in Kupffer cells.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 037 
KW  - lactate output
KW  - glucose
KW  - complement
KW  - flow
KW  - prostaglandin-f2-alpha
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16716
ER  - 
TY  - GEN
A1  - Püschel, Gerhard Paul
A1  - Miura, Hisayuki
A1  - Neuschäfer-Rube, Frank
A1  - Jungermann, Kurt
T1  - Inhibition by the protein kinase C activator 4β-phorbol 12-myristate 13-acetate of the prostaglandin F₂α-mediated and noradrenaline-mediated but not glucagon-mediated activation of glycogenolysis in rat liver
N2  - In perfused rat livers, infusion of prostaglandin F₂α (PGF₂α) or noradrenaline increased glucose and lactate output and reduced flow. Glucagon increased glucose output and decreased lactate output without influence on flow. Infusion of phorbol 13-myristate 14-acetate (PMA) for 20 min prior to these stimuli strongly inhibited the metabolic and hemodynamic effects of noradrenaline, reduced the metabolic actions of PGF₂α but did not alter the effects of glucagon. In isolated rat hepatocytes PGF₂α, noradrenaline and glucagon activated glycogen phosphorylase but only PGF₂α and noradrenaline increased intracellular inositol 1,4,5-1risphosphalc (InsP₃). The noradrenaline- or PGF₂α-elicited activation of glycogen phosphorylase and increase in InsP₃ were largely reduced after preincubation of the cells for 10 min with PMA, whereas the glucagon-mediated enzyme activation was not affected. In contra\t to PMA, the phorbol ester 4a-phorbol 13,14-didecanoate. which does not activate protein kinase C, did not attenuate the PGF₂α- and noradrenaline-elicited stimulation of glucose output, glycogen phosphorylase and InsP, formation. Stimulation of InsP₃ formation by AlF₄⁻, which activates phospholipase C independently of the receptor, was not attenuated by prior incubation with PMA. Plasma membranes purified from isolated hepatocytes had both a high-capacity, low-affinity and a low-capacity, high-affinity binding site for PGF₂α. The Kd of the high-capacity, low-affinity binding site was close to the concentration of PGF₂α that increased glycogen phosphorylase activity halfmaximally. Binding to the high-capacity, low-affinity binding site was enhanced by guanosine 5'- 0-(3-thio)triphosphate (GTP[S]). This high-capacity, low-affinity site might thus represent the receptor. The Bmax and Kd of the high-capacity site, as well as the enhancement by GTP[S] of PGF₂α binding to this site, remained unaffected by PMA pretreatment. It is concluded that, in hepatocytes, activation of protein kinase C by PMA interrupted the InsP₃-mediated signal pathway from PGF₂α via a PGF₂α receptor and phospholipase C to glycogen phosphorylase at a point distal of the receptor prior to phospholipase C.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 115 
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45889
ER  - 
TY  - GEN
A1  - Neuschäfer-Rube, Frank
A1  - Püschel, Gerhard Paul
A1  - Jungermann, Kurt
T1  - Characterization of prostaglandin-F₂α-binding sites on rat hepatocyte plasma membranes
N2  - Prostaglandin (PG)F₂α has previously been shown to increase glucose output from perfused livers and isolated hepatocytes, where it stimulated glycogen phosphorylase via an inositol-trisphosphatedependent signal pathway. In this study, PGF₂α binding sites on hepatocyte plasma membranes, that might represent the putative receptor, were characterized. Binding studies could not be performed with intact hepatocytes, because PGF₂α accumulated within the cells even at 4°C. The intracellular accumulation was an order of magnitude higher than binding to plasma membranes. Purified hepatocyte plasma membranes had a high-affinity/low-capacity and a low-affinity/highcapacity binding'site for PGF₂α. The respective binding constants for the high-affinity site were Kd = 3 nM and Bmax = 6 fmol/mg membrane protein, and for the low-affinity site Kd = 426 nM and Bmax = 245 fmol/mg membrane protein. Specific PGF₂α binding to the low-affinity site, but not to the high-affinity site, could be enhanced most potently by GTP[γS] followed by GDP[ϐS] and GTP, but not by ATP[γS] or GMP. PGF₂α competed most potently with [³H]PGF₂α for specific binding to hepatocyte plasma membranes, followed by PGD₂ and PGE₂. Since the low-affinity PGF₂α-binding site had a Kd in the concentration range in which PG had previously been shown to be half-maximally active, and since this binding site showed a sensitivity to GTP, it is concluded that it might represent the receptor involved in the PGF₂α signal chain in hepatocytes. A biological function of the high-affinity site is currently not known.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 113 
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45863
ER  - 
TY  - GEN
A1  - Püschel, Gerhard Paul
A1  - Kirchner, C.
A1  - Schröder, A.
A1  - Jungermann, Kurt
T1  - Glycogenolytic and antiglycogenolytic prostaglandin E₂ actions in rat hepatocytes are mediated via different signalling pathways
N2  - Prostaglandin E₂ has been reported both to stimulate glycogen-phosphorylase activity (glycogenolytic effect) and to inhibit the glucagon-stimulated glycogen-phosphorylase activity (antiglycogenolytic effect) in rat hepatocytes. It was the purpose of this study to resolve this apparent contradiction and to characterize the signalling pathways and receptor subtypes involved in the opposing prostaglandin E₂ actions. Prostaglandin E₂ (10 μM) increased glucose output, glycogen-phosphorylase activity and inositol trisphosphate formation in hepatocyte cell culture andor suspension. In the same systems, prostaglandin E₂ decreased the glucagon-stimulated (1 nM) glycogen-phosphorylase activity and cAMP formation. The signalling pathway leading to the glycogenolytic effect of PGE₂ was interrupted by incubation of the hepatocytes with 4P-phorbol 12-myristate 13-acetate (100 nM) for 10 min, while the antiglycogenolytic effect of prostaglandin E₂ was not attenuated. The signalling pathway leading to the antiglycogenolytic effect of prostaglandin E₂ was interrupted by an incubation of cultured hepatocytes with pertussis toxin (100 ng/ml) for 18 h, whereas the glycogenolytic effect of prostaglandin E₂ was enhanced. The EP₁/EP₃ prostaglandin-E₂-receptor-specific prostaglandin E₂ analogue Sulproston had a stronger glycogenolytic potency than the EP₃ prostaglandin-E₂-receptor-specific prostaglandin E₂ analogue Misoprostol. The antiglycogenolytic potency of both agonists was equal. It is concluded that the glycogenolytic and the antiglycogenolytic effects of prostaglandin E₂ are mediated via different signalling pathways in hepatocytes possibly involving EP₁ and EP₃ prostaglandin E₂ receptors, respectively.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 112 
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45853
ER  - 
TY  - JOUR
A1  - Anger, Horst
A1  - Walzel, Erwin
A1  - Kahrmann, Bettina
T1  - About the absorption of oligogalacturonates from the caecum of rats
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Rawel, Harshadrai Manilal
A1  - Muschiolik, Gerald
T1  - Effect of structural changes on foaming properties of soy proteins
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Stoof, Gisela
A1  - Anger, Horst
A1  - Kruse, Hans-Peter
T1  - The yield of resistant starch after hydrothermal treatment
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Kroll, Jürgen
A1  - Noack, Jutta
A1  - Rawel, Harshadrai Manilal
A1  - Kröck, Regina
A1  - Proll, Jürgen
T1  - Chemical reactions of benzyl isothio cyanate with egg-white protein fractions
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Kruse, Hans-Peter
A1  - Stoof, Gisela
A1  - Rubbert, Helga
A1  - Anger, Horst
T1  - Characterisation of fat replacers
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Husband, Fiona
A1  - Wilde, Peter J.
A1  - Clark, David C.
A1  - Rawel, Harshadrai Manilal
A1  - Muschiolik, Gerald
T1  - Foaming properties of modified faba bean protein isolates
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Kroll, Jürgen
A1  - Rawel, Harshadrai Manilal
A1  - Kröck, Regina
A1  - Proll, Jürgen
A1  - Schnaak, W.
T1  - Interactions of Isothiocyanates with egg white proteins
Y1  - 1994
ER  - 
TY  - GEN
A1  - Püschel, Gerhard Paul
A1  - Christ, Bruno
T1  - Inhibition by PGE₂ of glucagon-induced increase in phosphoenolpyruvate carboxykinase mRNA and acceleration of mRNA degradation in cultured rat hepatocytes
N2  - In cultured rat hepatocytes the key gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PCK) is known to be induced by glucagon via an elevation of cAMP. Prostaglandin E₂ has been shown to antagonize the glucagon-activated cAMP formation, glycogen phosphorylase activity and glucose output in hepatocytes. It was the purpose of the current investigation to study the potential of PGE₂ to inhibit the glucagon-induced expression of PCK on the level of mRNA and enzyme activity. PCK mRNA and enzyme activity were increased by 0.1 nM glucagon to a maximum after 2 h and 4 h, respectively. This increase was completely inhibited if 10 μM PGE2 was added concomitantly with glucagon. This inhibition by PGE₂ of glucagon-induced PCK activity was abolished by pertussis toxin treatment. When added at the maximum of PCK mRNA at 2 h, PGE₂ accelerated the decay of mRNA and reduced enzyme activity. This effect was not reversed by pertussis toxin treatment. Since in liver PGE₂ is derived from Kupffer cells, which play a key role in the local inflammatory response, the present data imply that during inflammation PGE₂ may reduce the hepatic gluconeogenic capacity via a Gᵢ-linked signal chain.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 045 
KW  - Prostaglandin E₂
KW  - Glucagon
KW  - Phosphoenolpyruvate carboxykinase
KW  - Inflammation
KW  - mRNA degradation
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45792
ER  - 
TY  - GEN
A1  - Neuschäfer-Rube, Frank
A1  - DeVries, Christa
A1  - Hänecke, Kristina
A1  - Jungermann, Kurt
A1  - Püschel, Gerhard Paul
T1  - Molecular cloning and expression of a prostaglandin E₂ receptor of the EP₃ϐ subtype from rat hepatocytes
N2  - Rat hepatocytes have previously been reported to possess prostaglandin E₂ receptors of the EP₃-type (EP₃-receptors) that inhibit glucagonstimulated glycogenolysis by decreasing cAMP. Here, the isolation of a functional EP₃ϐ receptor cDNA clone from a rat hepatocyte cDNA library is reported. This clone can be translated into a 362-amino-acid protein, that displays over 95% homology to the EP₃ϐ receptor from mouse mastocytoma. The amino- and carboxy-terminal region of the protein are least conserved. Transiently transfected HEK 293 cells expressed a single binding site for PGE₂ with an apparent Kd of 15 nM. PGE₂ > PGF₂α > PGD₂ competed for [³H]PGE₂ binding sites as did the EP₃ receptor agonists M&B 28767 = sulprostone > misoprostol but not the EP₁ receptor antagonist SC 19220. In stably transfected CHO cells M&B 28767 > sulprostone = PGE₂ > misoprostol > PGF₂α inhibited the forskolin-elicited cAMP formation. Thus, the characteristics of the EP₃ϐ receptor of rat hepatocytes closely resemble those of the EP₃ϐ receptor of mouse mastocytoma.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 108 
KW  - Prostaglandin receptor
KW  - Hepatocyte (rat)
KW  - Molecular cloning and expression
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45830
ER  - 
TY  - GEN
A1  - Watanabe, Yuji
A1  - Püschel, Gerhard Paul
A1  - Gardemann, Andreas
A1  - Jungermann, Kurt
T1  - Presinusoidal and proximal intrasinusoidal confluence of hepatic artery and portal vein in rat liver : functional evidence by orthograde and retrograde bivascular perfusion
N2  - The site of confluence of the artery and the portal vein in the liver still appears to be controversial. Anatomical studies suggested a presinusoidal or an intrasinusoidal confluence in the first, second or even final third of the sinusoids. The objective of this investigation was to study the problem with functional biochemical techniques. Rat livers were perfused through the hepatic artery and simultaneously either in the orthograde direction from the portal vein to the hepatic vein or in the retrograde direction from the hepatic vein to the portal vein. Arterial how was linearly dependent on arterial pressure between 70 cm H2O and 120 cm H2O at a constant portal or hepatovenous pressure of 18 cm H2O. An arterial pressure of 100 cm H2O was required for the maintenance of a homogeneous orthograde perfusion of the whole parenchyma and of a physiologic ratio of arterial to portal how of about 1:3. Glucagon was infused either through the artery or the portal vein and hepatic vein, respectively, to a submaximally effective ''calculated'' sinusoidal concentration after mixing of 0.1 nmol/L. During orthograde perfusions, arterial and portal glucagon caused the same increases in glucose output. Yet during retrograde perfusions, hepatovenous glucagon elicited metabolic alterations equal to those in orthograde perfusions, whereas arterial glucagon effected changes strongly reduced to between 10% and 50%. Arterially infused trypan blue was distributed homogeneously in the parenchyma during orthograde perfusions, whereas it reached clearly smaller areas of parenchyma during retrograde perfusions. Finally, arterially applied acridine orange was taken up by all periportal hepatocytes in the proximal half of the acinus during orthograde perfusions but only by a much smaller portion of periportal cells in the proximal third of the acinus during retrograde perfusions. These findings suggest that in rat liver, the hepatic artery and the portal vein mix before and within the first third of the sinusoids, rather than in the middle or even last third.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 067 
KW  - Hepatic artery
KW  - Portal vein
KW  - Confluence
KW  - Rat
KW  - Animal
KW  - Experimental study
KW  - Anatomy
KW  - Biochemical analysis
KW  - Technique
KW  - Perfusion
KW  - Exploration
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16702
ER  - 
TY  - GEN
A1  - Hespeling, Ursula
A1  - Jungermann, Kurt
A1  - Püschel, Gerhard Paul
T1  - Feedback-inhibition of glucagon-stimulated glycogenolysis in hepatocyte/kupffer cell cocultures by glucagon-elicited prostaglandin production in kupffer cells
N2  - Prostaglandins, released from Kupffer cells, have been shown to mediate the increase in hepatic glycogenolysis by various stimuli such as zymosan, endotoxin, immune complexes, and anaphylotoxin C3a involving prostaglandin (PG) receptors coupled to phospholipase C via a G(0) protein. PGs also decreased glucagon-stimulated glycogenolysis in hepatocytes by a different signal chain involving PGE(2) receptors coupled to adenylate cyclase via a G(i) protein (EP(3) receptors). The source of the prostaglandins for this latter glucagon-antagonistic action is so far unknown. This study provides evidence that Kupffer cells may be one source: in Kupffer cells, maintained in primary culture for 72 hours, glucagon (0.1 to 10 nmol/ L) increased PGE(2), PGF(2 alpha), and PGD(2) synthesis rapidly and transiently. Maximal prostaglandin concentrations were reached after 5 minutes. Glucagon (1 nmol/L) elevated the cyclic adenosine monophosphate (cAMP) and inositol triphosphate (InsP(3)) levels in Kupffer cells about fivefold and twofold, respectively. The increase in glyco gen phosphorylase activity elicited by 1 nmol/L glucagon was about twice as large in monocultures of hepatocytes than in cocultures of hepatocytes and Kupffer cells with the same hepatocyte density. Treatment of cocultures with 500 mu mol/L acetylsalicylic acid (ASA) to irreversibly inhibit cyclooxygenase (PGH-synthase) 30 minutes before addition of glucagon abolished this difference. These data support the hypothesis that PGs produced by Kupffer cells in response to glucagon might participate in a feedback loop inhibiting glucagon-stimulated glycogenolysis in hepatocytes.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 036 
KW  - perfused-rat-liver
KW  - aggregated immunoglobulin-g
KW  - intercellular communication
KW  - adenylate-cyclase
KW  - arachidonic-acid
KW  - activation
KW  - glucose
Y1  - 1995
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16697
ER  - 
TY  - JOUR
A1  - Dräger, Silke
A1  - Muschiolik, Gerald
A1  - Rawel, Harshadrai Manilal
T1  - Behaviour of whey protein stabilised emulsions
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Dräger, Silke
A1  - Muschiolik, Gerald
A1  - Rawel, Harshadrai Manilal
T1  - Molecular and emulsifying behaviour of pea proteins
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Müller, Silke
A1  - Rawel, Harshadrai Manilal
A1  - Muschiolik, Gerald
T1  - Surface activity of modified soy proteins
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Ozierenski, Bärbel
A1  - Stark, Claudia
A1  - Walzel, Erwin
T1  - Effects of pectin on lead-specific biomarkers and hepatic and extra hepatic biotransformation enzymes in lead- exposed rats
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Rawel, Harshadrai Manilal
A1  - Muschiolik, Gerald
T1  - Changes in molecular structure and functionality during purification and denaturation of faba bean protein
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Rawel, Harshadrai Manilal
A1  - Kroll, Jürgen
T1  - Some aspects of reactions of benzyl isothiocyanate with bovine sarcoplasmic proteins
Y1  - 1995
ER  - 
TY  - BOOK
ED  - Rothe, Manfred
ED  - Kruse, Hans-Peter
T1  - Aroma perception, formation, evaluation : proceedings of the 4th Wartburg Aroma Symposium
Y1  - 1995
PB  - Eigenverl.
CY  - Bergholz-Rehbrücke
ER  - 
TY  - JOUR
A1  - Stark, Claudia
A1  - Walzel, Erwin
A1  - Dongowski, Gerhard
A1  - Ozierenski, Bärbel
T1  - Influence of pectin on lead incorporation in germ-free and conventionalized rats
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Muschiolik, Gerald
A1  - Dräger, Silke
A1  - Rawel, Harshadrai Manilal
A1  - Gunning, Paul
A1  - Clark, David C.
T1  - Preliminary investigations of the functions of whey protein preparations in O/W systems
Y1  - 1995
ER  - 
TY  - GEN
A1  - Hespeling, Ursula
A1  - Püschel, Gerhard Paul
A1  - Jungermann, Kurt
A1  - Götze, Otto
A1  - Zwirner, Jörg
T1  - Stimulation of glycogen phosphorylase in rat hepatocytes via prostanoid release from Kupffer cells by recombinant rat anaphylatoxin C5a but not by native human C5a in hepatocyte/Kupffer cell co-cultures
N2  - Human anaphylatoxin C3a had previously been shown to increase glycogenolysis in perfused rat liver and prostanoid formation in rat liver macrophages. Surprisingly, human C5a, which in other systems elicited stronger responses than C3a, did not increase glycogenolysis in perfused rat liver. Species incompatibilities within the experimental system had been supposed to be the reason. The current study supports this hypothesis: (1) In rat liver macrophages that had been maintained in primary culture for 72 h recombinant rat anaphylatoxin C5a in concentrations between 0.1 and 10 pg/ml increased the formation of thromboxane A₂, prostaglandin D₂, E₂ and F₂α6- to 12-fold over basal within 10 min. In contrast, human anaphylatoxin C5a did not increase prostanoid formation in rat Kupffer cells. (2) The increase in prostanoid formation by recombinant rat C5a was specific. It was inhibited by a neutralizing monoclonal antibody. (3) In co-cultures of rat hepatocytes and rat Kupffer cells but not in hepatocyte mono-cultures recombinant rat C5a increased glycogen phosphorylase activity 3-fold over basal. This effect was inhibited by incubation of the co-cultures with 500 μM acetylsalicyclic acid. Thus, C5a generated either locally in the liver or systemically e.g. in the course of sepsis, may increase hepatic glycogenolysis by a prostanoid-mediated intercellular communication between Kupffer cells and hepatocytes.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 117 
Y1  - 1995
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45909
ER  - 
TY  - JOUR
A1  - Hernandez-Triana, Manuel
A1  - Kroll, Jürgen
A1  - Proll, Jürgen
A1  - Noack, Jutta
A1  - Petzke, Klaus-Jürgen
T1  - Benzyl-isothiocyanate (BITC) decreases quality of egg white proteins in rats
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Kroll, Jürgen
A1  - Rawel, Harshadrai Manilal
T1  - Chemical reactions of benzyl isothiocyanate with myoglobin
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Stark, Claudia
A1  - Kahrmann, Bettina
A1  - Walzel, Erwin
T1  - Epi- and methaphyseal morphology in long bones in BD IX, Han rats
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Krieger, K.
T1  - Effect of ß-carotene feeding on vitamin A and retinol-binding protein in the uterine fluid of pigs
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Raila, Jens
A1  - Eisenach, C.
A1  - Buchholz, Ingeborg
T1  - Distribution of vitamin A and retinol-binding-protein (RBP) in plasma, urine and various tissues of canines
Y1  - 1997
ER  - 
TY  - BOOK
ED  - Kruse, Hans-Peter
ED  - Rothe, Manfred
T1  - Flavour perception, aroma evaluation
Y1  - 1997
PB  - Eigenverl.
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Raila, Jens
A1  - Eisenach, C.
A1  - Buchholz, Ingeborg
A1  - Schweigert, Florian J.
T1  - Distribution of vitamin A and retinol-binding-protein (RBP) in various tissue of dogs and reccoon dogs
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Raila, Jens
A1  - Bok, V.
A1  - Buchholz, Ingeborg
A1  - Schweigert, Florian J.
T1  - Investigations on the excretion of vitamin A as retinol and retinyl esters bound to a high molecular complex
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Rawel, Harshadrai Manilal
A1  - Kroll, Jürgen
A1  - Riese-Schneider, Brigitte
A1  - Haebel, Sophie
T1  - Changes in physico-chemical and enzymatic properties of benzyl isothiocyanate derivatized proteinases
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Baumane, Anita
A1  - Buchholz, Ingeborg
A1  - Schoon, Heinz-Adolf
T1  - ß-Carotene accumulation in lung tissue of rats fed different types of fat
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Hacker, Hans-Jörg
A1  - Steinberg, Pablo
A1  - Bannasch, Peter
T1  - Pyruvate kinase isoenzyme shift from L-type to M2-type is a late event in hepatocarcinogenesis induced in rats by a choline-deficient/DL-ethionine supplemented diet
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Rawel, Harshadrai Manilal
A1  - Kroll, Jürgen
A1  - Riese-Schneider, Brigitte
A1  - Haebel, Sophie
T1  - Physicochemical and enzymatic properties of Benzyl-Isothiocyanate derivatized proteinases
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Rawel, Harshadrai Manilal
A1  - Kroll, Jürgen
A1  - Schröder, Insa Sigrid
T1  - In vitro enzymatic digestion of benzyl- and phenylisothiocyanate derivatized food proteins
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Kroll, Jürgen
A1  - Rawel, Harshadrai Manilal
A1  - Kröck, Regina
T1  - Microwave digestion of proteins
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Rawel, Harshadrai Manilal
A1  - Kroll, Jürgen
A1  - Schröder, Insa Sigrid
T1  - Reactions of isothiocyanates with food proteins : influence on enzyme activity and degradation
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Buchholz, Ingeborg
A1  - Bonitz, K.
T1  - Effect of age on the levels of retinol and retinyl ester in blood plasma, liver and kidney of dogs
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
T1  - Metabolism of carotenoids in mammals
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Raila, Jens
A1  - Haebel, Sophie
T1  - Vitamin A excreted in the urine of canines is associated with a Tamm-Horsfall-like Glycoprotein
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Neuschäfer-Rube, Frank
A1  - Oppermann, Martin
A1  - Möller, Ulrike
A1  - Böer, Ulrike
A1  - Püschel, Gerhard Paul
T1  - Agonist-induced phosphorylation by G protein-coupled receptor kinases of the EP4 receptor carboxyl-terminal domain in an EP3/EP4 prostaglandin E(2) receptor hybrid
N2  - Prostaglandin E(2) receptors (EP-Rs) belong to the family of heterotrimeric G protein-coupled ectoreceptors with seven transmembrane domains. They can be subdivided into four subtypes according to their ligand-binding and G protein-coupling specificity: EP1 couple to G(q), EP2 and EP4 to G(s), and EP3 to G(i). The EP4-R, in contrast to the EP3beta-R, shows rapid agonist-induced desensitization. The agonist-induced desensitization depends on the presence of the EP4-R carboxyl-terminal domain, which also confers desensitization in a G(i)-coupled rEP3hEP4 carboxyl-terminal domain receptor hybrid (rEP3hEP4-Ct-R). To elucidate the possible mechanism of this desensitization, in vivo phosphorylation stimulated by activators of second messenger kinases, by prostaglandin E(2), or by the EP3-R agonist M&B28767 was investigated in COS-7 cells expressing FLAG-epitope-tagged rat EP3beta-R (rEP3beta-R), hEP4-R, or rEP3hEP4- Ct-R. Stimulation of protein kinase C with phorbol-12-myristate-13-acetate led to a slight phosphorylation of the FLAG- rEP3beta-R but to a strong phosphorylation of the FLAG-hEP4-R and the FLAG-rEP3hEP4-Ct-R, which was suppressed by the protein kinase A and protein kinase C inhibitor staurosporine. Prostaglandin E(2) stimulated phosphorylation of the FLAG- hEP4-R in its carboxyl-terminal receptor domain. The EP3-R agonist M&B28767 induced a time- and dose-dependent phosphorylation of the FLAG-rEP3hEP4-Ct-R but not of the FLAG-rEP3beta-R. Agonist-induced phosphorylation of the FLAG- hEP4-R and the FLAG-rEP3hEP4-Ct-R were not inhibited by staurosporine, which implies a role of G protein-coupled receptor kinases (GRKs) in agonist-induced receptor phosphorylation. Overexpression of GRKs in FLAG-rEP3hEP4-Ct-R- expressing COS-7 cells augmented the M&B28767-induced receptor phosphorylation and receptor sequestration. These findings indicate that phosphorylation of the carboxyl-terminal hEP4-R domain possibly by GRKs but not by second messenger kinases may be involved in rapid agonist-induced desensitization of the hEP4-R and the rEP3hEP4-Ct-R.
Y1  - 1999
SN  - 1521-0111
ER  - 
TY  - JOUR
A1  - Rehwald, Matthias
A1  - Neuschäfer-Rube, Frank
A1  - DeVries, Christa
A1  - Püschel, Gerhard Paul
T1  - Possible role for ligand binding of histidine 81 in the second transmembrane domain of the rat prostaglandin F2alpha receptor
N2  - For the five principal prostanoids PGD2, PGE2, PGF2alpha, prostacyclin and thromboxane A2 eight receptors have been identified that belong to the family of G-protein-coupled receptors. They display an overall homology of merely 30%. However, single amino acids in the transmembrane domains such as an Arg in the seventh transmembrane domain are highly conserved. This Arg has been identified as part of the ligand binding pocket. It interacts with the carboxyl group of the prostanoid. The aim of the current study was to analyze the potential role in ligand binding of His-81 in the second transmembrane domain of the rat PGF2alpha receptor, which is conserved among all PGF2alpha receptors from different species. Molecular modeling suggested that this residue is located in close proximity to the ligand binding pocket Arg 291 in the 7th transmembrane domain. The His81 (H) was exchanged by site-directed mutagenesis to Gln (Q), Asp (D), Arg (R), Ala (A) and Gly (G). The receptor molecules were N-terminally extended by a Flag epitope for immunological detection. All mutant proteins were expressed at levels between 50% and 80% of the wild type construct. The H81Q and H81D receptor bound PGF2alpha with 2-fold and 25-fold lower affinity, respectively, than the wild type receptor. Membranes of cells expressing the H81R, H81A or H81G mutants did not bind significant amounts of PGF2alpha. Wild type receptor and H81Q showed a shallow pH optimum for PGF2alpha binding around pH 5.5 with almost no reduction of binding at higher pH. In contrast the H81D mutant bound PGF2alpha with a sharp optimum at pH 4.5, a pH at which the Asp side chain is partially undissociated and may serve as a hydrogen bond donor as do His and Gln at higher pH values. The data indicate that the His-81 in the second transmembrane domain of the PGF2alpha receptor in concert with Arg-291 in the seventh transmembrane domain may be involved in ligand binding, most likely not by ionic interaction with the prostaglandin's carboxyl group but rather as a hydrogen bond donor.
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Fennekohl, Alexandra
A1  - Schieferdecker, Henrike L.
A1  - Jungermann, Kurt
A1  - Püschel, Gerhard Paul
T1  - Differential expression of prostanoid receptors in hepatocytes, Kupffer cells, sinusoidal endothelial cells and stellate cells of rat liver
N2  - BACKGROUND/AIMS: Prostanoids produced by nonparenchymal cells modulate the function of parenchymal and nonparenchymal liver cells during homeostasis and inflammation via eight classes of prostanoid receptors coupled to different G-proteins. Prostanoid receptor expression in parenchymal and nonparenchymal cells was studied in order to get a better insight into the complex prostanoid-mediated intrahepatic signaling network. METHODS: RNA was isolated from freshly purified parenchymal and nonparenchymal rat liver cells and the mRNA level of all eight prostanoid receptor classes was determined by newly developed semiquantitative reverse transcription-polymerase chain reaction protocols. RESULTS: The mRNAs for the prostanoid receptors were differentially expressed. Hepatocytes were the only cell type which contained the mRNA of the Gq-linked prostaglandin F2alpha receptor; they were devoid of any mRNA for the Gs-linked prostanoid receptors. Kupffer cells possessed the largest amount of mRNA for the Gs-linked prostaglandin E2 receptor subtype 2. Endothelial cells expressed high levels of mRNA for the Gq-linked thromboxane receptor and medium levels of mRNA for the Gs-linked prostacyclin receptor, while stellate cells had the highest levels of mRNA for the prostacyclin receptor. The mRNAs for the Gq-linked prostaglandin E2 receptor subtype 1 and the Gi-linked prostaglandin E2 receptor subtype 3 were expressed in hepatocytes and all nonparenchymal cell types at similar high levels, whereas the mRNA of the Gs-linked prostaglandin D2 receptor was expressed in all nonparenchymal cells at very low levels. CONCLUSIONS: In hepatocytes the prostaglandin F2alpha receptor can mediate an increase in glucose output via an increase of intracellular InsP3 while cAMP-dependent glucose output can be inhibited via the subtype 3 prostaglandin E2 receptor. The subtype 2 prostaglandin E2 receptor can restrain the inflammatory response of Kupffer cells via an increase in intracellular cAMP The thromboxane receptor and the prostacyclin receptor in sinusoidal endothelial and the prostacyclin receptor in stellate cells may be involved in the regulation of sinusoidal blood flow and filtration.
Y1  - 1999
SN  - 0168-8278
ER  - 
TY  - JOUR
A1  - Schieferdecker, Henrike L.
A1  - Pestel, Sabine
A1  - Püschel, Gerhard Paul
A1  - Götze, Otto
T1  - Increase by anaphylatoxin C5a of glucose output in perfused rat liver via prostanoids derived from nonparenchymal cells : direct action of prostaglandins and indirect action of thromboxane A(2) on hepatocytes
N2  - In the perfused rat liver the anaphylatoxin C5a enhanced glucose output, reduced flow, and elevated prostanoid overflow. Because hepatocytes (HCs) do not express C5a receptors, the metabolic C5a actions must be indirect, mediated by e.g. prostanoids from Kupffer cells (KCs) and hepatic stellate cells (HSCs), which possess C5a receptors. Surprisingly, the metabolic C5a effects were not only impaired by the prostanoid synthesis inhibitor, indomethacin, but also by the thromboxane A(2) (TXA(2)) receptor antagonist, daltroban, even though HCs do not express TXA(2) receptors. TXA(2) did not induce prostaglandin (PG) or an unknown factor release from KCs or sinusoidal endothelial cells (SECs), which express TXA(2) receptors, because (1) daltroban did neither influence the C5a-induced release of prostanoids from cultured KCs nor the C5a-dependent activation of glycogen phosphorylase in KC/HC cocultures and because (2) the TXA(2) analog, U46619, failed to stimulate prostanoid release from cultured KCs or SECs or to activate glycogen phosphorylase in KC/HC or SEC/HC cocultures. In the perfused liver, Ca(2+)-deprivation inhibited not only flow reduction but also glucose output elicited by C5a to similar extents as daltroban. Similarly, in the absence of extracellular Ca(2+), flow reduction and glucose output induced by U46619 were almost completely prevented, whereas glucose output induced by the directly acting PGF(2alpha) was only slightly lowered. Thus, in the perfused rat liver PGs released after C5a- stimulation from KCs and HSCs directly activated glycogen phosphorylase in HCs, and TXA(2) enhanced glucose output indirectly mainly by causing hypoxia as a result of flow reduction.
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Rothe, Manfred
A1  - Kruse, Hans-Peter
T1  - Solving flavor problems by sensory methods
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Steinberg, Pablo
A1  - Klingelhöffer, Alexandra
A1  - Schäfer, Angelika
A1  - Wüst, Günter
A1  - Weiße, Günter
A1  - Oesch, Franz
A1  - Eigenbrodt, Erich
T1  - Expression of pyruvate kinase M2 in preneoplastic hepatic foci of N-nitrosomorpholine-treated rats
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Mazurek, Sybille
A1  - Eigenbrodt, Erich
A1  - Failing, Klaus
A1  - Steinberg, Pablo
T1  - Alterations in the glycolytic and glutaminolytic pathways after malignant transformation of rat liver oval cells
Y1  - 1999
ER  - 
TY  - THES
A1  - Jeckel, Andro
T1  - Dietary and blood determinants of antioxidant capacity of human blood plasma
Y1  - 1999
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Steinberg, Pablo
A1  - Fischer, Thomas M.
A1  - Arand, Michael
A1  - Park, Eunju
A1  - Elmadfa, Ibrahim
A1  - Rimkus, Gerhard
A1  - Brunn, Hubertus
A1  - Dienes, Hans-Peter
T1  - Acute hepatotoxicity of the polycyclic musk 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthaline (AHTN)
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Bluvshtein, Evgenia
A1  - Glass, George
A1  - Volohonsky, Gloria
A1  - Yaakubowitz, Margalit
A1  - Harness, Ella
A1  - Smorodinsky, Nechama
A1  - Seidel, Albrecht
A1  - Frank, Heinz
A1  - Stark, Avishay Abraham
A1  - Steinberg, Pablo
T1  - Inhibition of the hydrolytic and transpeptidatic activities of rat kidney gamma-glutamyltranspeptidase by specific monoclonal antibodies
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Bonitz, K.
A1  - Siegling, Christiane
A1  - Buchholz, Ingeborg
T1  - Distribution of vitamin A, retinol-binding protein (RBP), cellular retinoic acid binding protein (CRABPI) and retinoid X receptor ß (RXRß) in the porcine uterus during early gestation
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Kruse, Hans-Peter
A1  - Klessen, Brigitta
A1  - Blaut, Michael
T1  - Effects of inulin of faecal bifidobateria in human subjects
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Gottwald, C.
T1  - Effect of parturition on levels of vitamins A and E and of ß-carotene in plasma and milk of mares
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Schleger, C.
A1  - Becker, Rolf
A1  - Oesch, Franz
A1  - Steinberg, Pablo
T1  - The human p53 gene mutated at position 249 per se is not sufficient to immortalize human liver cells
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Hengstler, Jan Georg
A1  - VanDerBurg, Bart
A1  - Steinberg, Pablo
A1  - Oesch, Franz
T1  - Interspecies differences in cancer susceptibility and toxicity
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Steinberg, Pablo
A1  - Fischer, Thomas M.
A1  - Kiulies, Sandra
A1  - Biefang, Katja
A1  - Platt, Karl-Ludwig
A1  - Oesch, Franz
A1  - Böttger, Thomas
A1  - Bulitta, Clemens
A1  - Kempf, Peter
A1  - Hengstler, Jan Georg
T1  - Drug metabolizing capacity of cryopreserved human, rat and mouse liver parenchymal cells in suspension
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Neuschäfer-Rube, Frank
A1  - Möller, Ulrike
A1  - Püschel, Gerhard Paul
T1  - Structure of the 5'-flanking region of the rat prostaglandin f(2alpha) receptor
N2  - Prostaglandin F(2alpha) (PGF(2alpha)), modulates hepatocyte functions via a heptahelical G(q)-coupled PGF(2alpha)-receptor (FP-R) which in liver is expressed exclusively in hepatocytes. The aim of the present study was to isolate the 5'-flanking region of the rat FP-R gene and to elucidate its basal and IL-6-modulated transcription control function in rat hepatocytes. The 5'-non-translated region of the rat hepatocyte FP-R mRNA differed from the corresponding region in rat fetal astrocyte or corpus luteum. It was encoded by exons 1a and 2 which were separated by a 1. 4 kb intron containing the exons 1b and 1c coding for the 5'-untranslated region of rat fetal astrocyte and corpus luteum FP-R mRNA, respectively. The transcription initiation site in hepatocytes was localized 263 bp upstream of the start ATG by 5'-RACE. A DNA-fragment covering the 5'-flanking region of the rFP-R gene from - 1 of the transcription initiation site to -2590 bp was cloned and sequenced. Its 3'-two thirds had a 65% sequence identity to the mouse FP-R promoter however no homology to the bovine FP-R promoter. In the overlapping sequence most of the putative transcription factor binding sites were conserved between mouse and rat. The rat promoter contained no classical TATA- or CAAT-boxes but putative binding sites for the transcription factors C/EBP, GATA-1, HNF-1, HNF-3beta, SP-1, and USF. Luciferase reporter gene constructs containing portions of the 5'-flanking region were transfected into rat hepatocytes. Luciferase expression ranked -181 >/= -608 < -1418 > -1821 >/= -2590. The strongest transcriptional activity was conferred by the region between -608 and -1418 containing a cluster of potential HNF-1 and HNF-3beta binding sites that might allow the exclusive expression of FP-R mRNA in hepatocytes. The amount of FP-R mRNA and the luciferase expression under control of the -2590 promoter fragment were reduced by IL-6 in hepatocytes. Copyright 2000 Academic Press.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Fennekohl, Alexandra
A1  - Lucas, Maria
A1  - Püschel, Gerhard Paul
T1  - Induction by interleukin 6 of G(s)-coupled prostaglandin E(2) receptors in rat hepatocytes mediating a prostaglandin e(2)-dependent inhibition of the hepatocyte's acute phase response
N2  - Prostanoids, that are released from nonparenchymal liver cells in response to proinflammatory stimuli, are involved in the regulation of hepatic functions during inflammation. They exert their effects on their target cells via heptahelical receptors in the plasma membrane. For the 5 prostanoids prostaglandin E(2) (PGE(2)), prostaglandin F(2alpha), prostaglandin D(2) (PGD(2)), prostacyclin, and thromboxane A(2) there exist 8 receptors that are coupled to different heterotrimeric G proteins. These receptors are expressed differentially in the 4 principal liver cell types, i.e., hepatocytes, Kupffer cells, sinusoidal endothelial cells, and hepatic stellate cells. It was intriguing, that the messenger RNA (mRNA) of none of the G(s)-coupled prostanoid receptors (DP-R, EP2-R, EP4-R, and IP-R) that can attenuate the inflammatory reaction were present in hepatocytes. The current study shows that the expression of the G(s)-coupled prostanoid receptors EP2-R, EP4-R, and DP-R, but not the IP-R, was efficiently and rapidly up-regulated by treatment of hepatocytes in vitro or rats in vivo with the key acute phase cytokine interleukin 6 (IL-6). In IL-6-treated hepatocytes PGE(2) in turn attenuated the IL-6-induced alpha(2)-macroglobulin formation via a cyclic adenosine monophosphate (cAMP)- dependent signal chain. The data indicate that an IL-6-mediated induction of the previously not expressed EP2-R and EP4- R on hepatocytes might establish a prostanoid-mediated feedback inhibition loop for the attenuation of the acute phase response.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Böer, Ulrike
A1  - Neuschäfer-Rube, Frank
A1  - Möller, Ulrike
A1  - Püschel, Gerhard Paul
T1  - Requirement of N-glycosylation of the prostaglandin E2 receptor EP3beta for correct sorting to the plasma membrane but not for correct folding
N2  - Eight heptahelical receptors have been characterized for prostaglandin (PG) D(2), PGE(2), PGF(2alpha), prostacyclin and thromboxane A(2). They share a sequence identity of 40%. All of them have potential N-glycosylation sites. The current study analysed the role of the two N-glycosylation sites in the rat EP3beta-subtype PGE(2) receptor for protein folding and sorting. The N-glycosylation consensus sequences were eliminated by site-directed mutagenesis and receptors expressed in HEK-293 cells. Both potential N-glycosylation sites were used. Their joint elimination resulted in the synthesis of a receptor protein with full binding competence, biological activity and no reduction of affinity; however, the half-life of the non-glycosylated receptor was slightly reduced. Ligand binding to intact stably transfected cells and confocal laser microscopic immunocytochemistry showed that the glycosylated receptor was correctly inserted into the plasma membrane to a much larger extent than the non-glycosylated receptor, which tended to accumulate in the perinuclear zone of the endoplasmic reticulum. Inhibition of N-glycosylation with tunicamycin resulted in a similar perinuclear distribution of the wild-type receptor. Therefore, glycosylation of the EP3beta receptor seems not to be necessary for correct folding of the receptor protein but for the efficient transport of the receptor protein to the plasma membrane. This contrasts with a previous finding which described a reduction of the affinity for PGE(2) of the EP3alpha receptor by elimination of the distal glycosylation site when the receptor protein was expressed in insect cells.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Rawel, Harshadrai Manilal
A1  - Kroll, Jürgen
A1  - Riese, B.
T1  - Reaction of chlorogenic acid with lysozyme : physicochemical characterization and proteolytic digestion of the derivatives
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Kroll, Jürgen
A1  - Rawel, Harshadrai Manilal
T1  - Reactions of plant phenols with myoglobin : influence of chemical structure of the phenolic compounds
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Kroll, Jürgen
A1  - Rawel, Harshadrai Manilal
A1  - Seidelmann, N.
T1  - Physicochemical properties and susceptibility to proteolytic digestionof myoglobin-phenol derivatives
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Rawel, Harshadrai Manilal
A1  - Kroll, Jürgen
A1  - Rohn, Sascha
T1  - Reactions of phenol substances with lysozyme - physicochemical characterisation and proteolytic digestion of the derivatives
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Baumane, Anita
A1  - Buchholz, Ingeborg
A1  - Schoon, Heinz-Adolf
T1  - Plasma and tissue concentrations of ß-carotene and vitamin A in rats fed ß-carotene in various fats of plant and animal origin
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Raila, Jens
A1  - Buchholz, Ingeborg
A1  - Aupperle, Heike
A1  - Raila, Jens
A1  - Schoon, Heinz-Adolf
A1  - Schweigert, Florian J.
T1  - The distribution of vitamin A and retinol-binding protein (RBP) in the blood plasma, urine, liver and kidney of carnivores
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Hurtienne, Andrea
A1  - Bathe, Katharina
T1  - Improved extraction procedure for carotenoids from human milk
Y1  - 2000
SN  - 0300-9831
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Steinhagen, Beate
A1  - Trüpschuch, Annett
A1  - Siemann, A.
A1  - Büscher, Ulrich
A1  - Dudenhausen, Joachim W.
T1  - Transfer of carotenoids, alfa-tocopherol and retinol from plasma into follicular fluid in women
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Baumane, Anita
A1  - Leo, M.
A1  - Wahren, H.
A1  - Gürtler, H.
T1  - The effect of an iron supplementation on plasma levels of the vitamins A, E and C in piglets
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Bok, V.
T1  - Vitamin A in blood plasma and urine of dogs is affected by the dietary level of vitamin A
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Hengstler, Jan Georg
A1  - Utesch, D.
A1  - Steinberg, Pablo
T1  - Cryopreserved primary hepatocytes as a constantly available in vitro model for the evaluation of human and animal drug metabolism and enzyme induction
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Schleger, C.
A1  - Heck, R.
A1  - Steinberg, Pablo
T1  - The role of wild-type and mutated N-ras in the malignant transformation of liver cells
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Hengstler, Jan Georg
A1  - Ringel, M.
A1  - Biefang, Katja
A1  - Hammel, S.
A1  - Milbert, U.
A1  - Gerl, M.
A1  - Klebach, M.
A1  - Diener, B.
A1  - Platt, Karl-Ludwig
A1  - Böttger, Thomas
A1  - Steinberg, Pablo
A1  - Oesch, Franz
T1  - Cultures with cryopreserved hepatocytes : applicability for studies of enzyme induction
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Steinhagen, Beate
A1  - Siemann, A.
A1  - Büscher, Ulrich
A1  - Dudenhausen, Joachim W.
A1  - Schweigert, Florian J.
T1  - Carotenoids, retinol and tocopherol in plasma and follicular fluid of women
Y1  - 2000
ER  - 
TY  - THES
A1  - Metges, Cornelia C.
T1  - Investigations on kinetics and dietary requirements of amino acids in healthy adults using stable isotope tracer techniques
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Rawel, Harshadrai Manilal
A1  - Rohn, Sascha
A1  - Kroll, Jürgen
T1  - Reactions of selected secondary plant metabolites (glucosinolates and phenols) with food proteins and enzymes - Influence on physicochemical properties, enzyme activity and proteolytic dagradation
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Rühl, Ralph
A1  - Sass, Jörn Oliver
A1  - Nau, Heinz
A1  - Klug, Stephan
T1  - Effects of all-trans-retinoic acid and all-trans-retinoyl glucuronide in two in vitro systems of distinct biological complexity
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Macias, Consuelo
A1  - Schweigert, Florian J.
T1  - Changes in the Concentration of Carotenoids, Vitamin A, Alpha-Tocopherol and Total Lipids in Human Milk throughout Early Lactation
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Buchholz, Ingeborg
A1  - Schumacher, A.
A1  - Gropp, J.
T1  - Effect of dietary ß-carotene on the accumulation of ß-carotene and vitamin A in plasma and tissues of gilts
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Kroll, Jürgen
A1  - Rawel, Harshadrai Manilal
T1  - Reactions of plant phenols with myoglobin : influence of chemical structure of the phenolic compounds
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Rawel, Harshadrai Manilal
A1  - Kroll, Jürgen
A1  - Hohl, U. C.
T1  - Model studies on reactions of plant phenols with whey proteins
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Elmazar, Mohamed M. A.
A1  - Rühl, Ralph
A1  - Nau, Heinz
T1  - Synergistic Teratogenic Effects Induced by Retinoids in Mice by Coadministration of a RARa- or RARy-Selective Agonist with a RXR-Selective Agonist
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
T1  - Milk more than a nutrient : Hormones, growth factors, and bioactive factors
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Siegling, Christiane
T1  - Immunolocalization of retinol-binding protein, cellular retinoic acid-binding protein I and retinoid X receptor ß in the porcine reproductive tract during the oestrus cycle
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Raila, Jens
A1  - Mathews, U.
A1  - Schweigert, Florian J.
T1  - Plasma transport and tissue distribution of ß-carotene, vitamin A and retinol-binding protein in domestic cats
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Rühl, Ralph
A1  - Thiel, Renate
A1  - Lacker, Tanja Silke
A1  - Srohschein, Sabine
A1  - Albert, Klaus
A1  - Nau, Heinz
T1  - Synthesis, high-performance liquid chromatography-nuclear magnetic resonance characterization and pharmacokinetics in mice of CD271 glucuronide
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Rühl, Ralph
A1  - Plum, Claudia
A1  - Elmazar, Mohamed M. A.
A1  - Nau, Heinz
T1  - Embryonic Subcellular Distribution of 13-cis- and All-trans-Retinoic Acid Indicates Differential Cytosolic/ Nuclear Localization
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Steinberg, Pablo
A1  - Zschaler, Ingrid
A1  - Thom, Elke
A1  - Kuna, Manuela
A1  - Wüst, Günter
A1  - Schäfer-Schwebel, Angelika
A1  - Müller, Rolf
A1  - Kramer, Peter-Jürgen
A1  - Weiße, Günter
T1  - The polycyclic musk 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthaline lacks liver tumor initiating and promoting activity in rats exposed to human-relevant doses
Y1  - 2001
UR  - http://www.springerlink.com/content/100462
U6  - https://doi.org/10.1007/s002040100274
SN  - 0340-5761
ER  - 
TY  - JOUR
A1  - Komlosh, A.
A1  - Volohonsky, Gloria
A1  - Porat, Noga
A1  - Tuby, chen n. y. h.
A1  - Bluvshtein, Evgenia
A1  - Steinberg, Pablo
A1  - Oesch, Franz
A1  - Stark, Avishay Abraham
T1  - Gamma-glutamyl transpeptidase and glutathione biosynthesis in non-tumorigenic and tumorigenic rat liver oval cell lines
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Kroll, Jürgen
A1  - Rawel, Harshadrai Manilal
A1  - Rohn, Sascha
A1  - Czajka, Dörte
T1  - Interactions of glycinin with plant phenols : influence on chemical properties and proteolytic degradation of the proteins
N2  - Soya glycinin was derivatized with different phenolic substances (caffeic-, chlorogenic-, gallic acid and quercetin). The protein derivatives formed have been characterized in terms of their properties where they showed changes in the content of free epsilon-amino groups, tryptophan and thiol groups. The derivatives have also been characterized in terms of their solubility at different pH-values to document the influence on the functional properties. Another objective of this paper was to demonstrate the influence on the digestibility of the proteins with one of the main enzymes of the gastro-intestinal tract (pancreatin) on the basis of in vitro experiments after derivatization with phenolic substances. The enzymatic digestion of the derivatized proteins was promoted.
Y1  - 2001
UR  - http://www3.interscience.wiley.com/cgi-bin/abstract/85513730
ER  - 
TY  - JOUR
A1  - Rohn, Sascha
A1  - Rawel, Harshadrai Manilal
A1  - Pietruschinski, Nadine
A1  - Kroll, Jürgen
T1  - In vitro inhibition of alpha -chymotryptic activity by phenolic compounds
N2  - alpha-Chymotrypsin was modified by covalent attachment of selected phenolic and related compounds (caffeic acid, chlorogenic acid, ferulic acid, gallic acid, quinic acid, m-/o-/p-dihydroxybenzene and p-benzoquinone) at pH 9. The derivatives formed were characterised in terms of their activity and selected physicochemical properties. In vitro experiments showed that the proteolytic digestion of food proteins with alpha-chymotrypsin derivatives was adversely affected. This decrease depended on the reactivity of the phenolic and related substances tested as well as on the kind of substrate applied. The derivatisation was accompanied by a reduction in the amount of free lysine and tryptophan residues. Moreover, the solubility of the derivatives decreased over a broad pH range, with a parallel increase in the hydrophobicity. The isoelectric point was shifted to a lower pH value, and formation of high-molecular-weight fractions was documented by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE).
Y1  - 2001
UR  - http://www3.interscience.wiley.com/cgi-bin/abstract/86510624
ER  -