@misc{HespelingPueschelJungermannetal.1995,
  author    = {Hespeling, Ursula and P{\"u}schel, Gerhard Paul and Jungermann, Kurt and G{\"o}tze, Otto and Zwirner, J{\"o}rg},
  title     = {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},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45909},
  year      = {1995},
  abstract  = {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.},
  language  = {en}
}
@misc{WatanabePueschelGardemannetal.1994,
  author    = {Watanabe, Yuji and P{\"u}schel, Gerhard Paul and Gardemann, Andreas and Jungermann, Kurt},
  title     = {Presinusoidal and proximal intrasinusoidal confluence of hepatic artery and portal vein in rat liver : functional evidence by orthograde and retrograde bivascular perfusion},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16702},
  year      = {1994},
  abstract  = {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.},
  language  = {en}
}
@misc{GardemannPueschelJungermann1992,
  author    = {Gardemann, Andreas and P{\"u}schel, Gerhard Paul and Jungermann, Kurt},
  title     = {Nervous control of liver metabolism and hemodynamics},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-51346},
  year      = {1992},
  abstract  = {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},
  language  = {en}
}
@misc{NeuschaeferRubeDeVriesHaeneckeetal.1994,
  author    = {Neusch{\"a}fer-Rube, Frank and DeVries, Christa and H{\"a}necke, Kristina and Jungermann, Kurt and P{\"u}schel, Gerhard Paul},
  title     = {Molecular cloning and expression of a prostaglandin E₂ receptor of the EP₃ϐ subtype from rat hepatocytes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45830},
  year      = {1994},
  abstract  = {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.},
  language  = {en}
}
@misc{PueschelMentleinHeymann1982,
  author    = {P{\"u}schel, Gerhard Paul and Mentlein, Rolf and Heymann, Eberhard},
  title     = {Isolation and characterization of Dipeptidyl Peptidase IV from human placenta},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45875},
  year      = {1982},
  abstract  = {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.},
  language  = {en}
}
@misc{PueschelJungermann1994,
  author    = {P{\"u}schel, Gerhard Paul and Jungermann, Kurt},
  title     = {Integration of function in the hepatic acinus : intercellular communication in neural and humoral control of liver metabolism},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-51279},
  year      = {1994},
  abstract  = {Content: Architecture of the liver acinus Functional zonation of the liver acinus Topological organization of metabollc regulation in the acinus Topological organization of defense and organ structure regulation in the acinus},
  language  = {de}
}
@misc{PueschelMiuraNeuschaeferRubeetal.1993,
  author    = {P{\"u}schel, Gerhard Paul and Miura, Hisayuki and Neusch{\"a}fer-Rube, Frank and Jungermann, Kurt},
  title     = {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},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45889},
  year      = {1993},
  abstract  = {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.},
  language  = {en}
}
@misc{PueschelChrist1994,
  author    = {P{\"u}schel, Gerhard Paul and Christ, Bruno},
  title     = {Inhibition by PGE₂ of glucagon-induced increase in phosphoenolpyruvate carboxykinase mRNA and acceleration of mRNA degradation in cultured rat hepatocytes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45792},
  year      = {1994},
  abstract  = {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.},
  language  = {en}
}
@misc{PueschelNathJungermann1987,
  author    = {P{\"u}schel, Gerhard Paul and Nath, Annegret and Jungermann, Kurt},
  title     = {Increase of urate formation by stimulation of sympathetic hepatic nerves, circulating noradrenaline and glucagon inthe perfused rat liver},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16728},
  year      = {1987},
  abstract  = {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.},
  language  = {en}
}
@misc{PueschelOppermannMuscholetal.1989,
  author    = {P{\"u}schel, Gerhard Paul and Oppermann, Martin and Muschol, Waldemar and G{\"o}tze, Otto and Jungermann, Kurt},
  title     = {Increase of glucose and lactate output and decrease of flow by human anaphylatoxin C3a but not C5a in perfused rat liver},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16733},
  year      = {1989},
  abstract  = {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.},
  language  = {en}
}