TY  - JOUR
A1  - Schildroth, Janice
A1  - Rettig-Zimmermann, Juliane
A1  - Kalk, Philipp
A1  - Steege, Andreas
A1  - Faehling, Michael
A1  - Sendeski, Mauricio
A1  - Paliege, Alexander
A1  - Lai, En Yin
A1  - Bachmann, Sebastian
A1  - Persson, Pontus B.
A1  - Hocher, Berthold
A1  - Patzak, Andreas
T1  - Endothelin type A and B receptors in the control of afferent and efferent arterioles in mice
JF  - Nephrology, dialysis, transplantation
N2  - Background. Endothelin 1 contributes to renal blood flow control and pathogenesis of kidney diseases. The differential effects, however, of endothelin 1 (ET-1) on afferent (AA) and efferent arterioles (EA) remain to be established.
 Methods. We investigated endothelin type A and B receptor (ETA-R, ETB-R) functions in the control of AA and EA. Arterioles of ETB-R deficient, rescued mice [ETB (-/-)] and wild types [ETB(+/+)] were microperfused.
 Results. ET-1 constricted AA stronger than EA in ETB (-/-) and ETB(+/+) mice. Results in AA: ET-1 induced similar constrictions in ETB(-/-) and ETB(+/+) mice. BQ-123 (ETA-R antagonist) inhibited this response in both groups. ALA-ET-1 and IRL1620 (ETB-R agonists) had no effect on arteriolar diameter. L-NAME did neither affect basal diameters nor ET-1 responses. Results in EA: ET-1 constricted EA stronger in ETB(+/+) compared to ETB(-/-). BQ-123 inhibited the constriction completely only in ETB(-/-). ALA-ET-1 and IRL1620 constricted only arterioles of ETB(+/+) mice. L-NAME decreased basal diameter in ETB(+/+), but not in ETB(-/-) mice and increased the ET-1 response similarly in both groups. The L-NAME actions indicate a contribution of ETB-R in basal nitric oxide (NO) release in EA and suggest dilatory action of ETA-R in EA.
 Conclusions. ETA-R mediates vasoconstriction in AA and contributes to vasoconstriction in EA in this mouse model. ETB-R has no effect in AA but mediates basal NO release and constriction in EA. The stronger effect of ET-1 on AA supports observations of decreased glomerular filtration rate to ET-1 and indicates a potential contribution of ET-1 to the pathogenesis of kidney diseases.
KW  - endothelin
KW  - ETB receptor-deficient mouse
KW  - glomerular arterioles
KW  - renal haemodynamics
Y1  - 2011
U6  - https://doi.org/10.1093/ndt/gfq534
SN  - 0931-0509
VL  - 26
IS  - 3
SP  - 779
EP  - 789
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Vignon-Zellweger, Nicolas
A1  - Relle, Katharina
A1  - Kienlen, Elodie
A1  - Alter, Markus L.
A1  - Seider, Patrick
A1  - Sharkovska, Juliya
A1  - Heiden, Susi
A1  - Kalk, Philipp
A1  - Schwab, Karima
A1  - Albrecht-Kuepper, Barbara
A1  - Theuring, Franz
A1  - Stasch, Johannes-Peter
A1  - Hocher, Berthold
T1  - Endothelin-1 overexpression restores diastolic function in eNOS knockout mice
JF  - Journal of hypertension
N2  - Background The cardiac nitric oxide and endothelin-1 (ET-1) systems are closely linked and play a critical role in cardiac physiology. The balance between both systems is often disturbed in cardiovascular diseases. To define the cardiac effect of excessive ET-1 in a status of nitric oxide deficiency, we compared left ventricular function and morphology in wild-type mice, ET-1 transgenic (ET+/+) mice, endothelial nitric oxide synthase knockout (eNOS(-/-)) mice, and ET(+/+)eNOS(-/-) mice.
 Methods and results eNOS(-/-) and ET(+/+)eNOS(-/-) mice developed high blood pressure compared with wild-type and ET+/+ mice. Left ventricular catheterization showed that eNOS(-/-) mice, but not ET(+/+)eNOS(-/-), developed diastolic dysfunction characterized by increased end-diastolic pressure and relaxation constant tau. To elucidate the causal molecular mechanisms driving the rescue of diastolic function in ET(+/+)eNOS(-/-) mice, the cardiac proteome was analyzed. Two-dimensional gel electrophoresis coupled to mass spectrometry offers an appropriate hypothesis-free approach. ET-1 overexpression on an eNOS(-/-) background led to an elevated abundance and change in posttranslational state of antioxidant enzymes (e. g., peroxiredoxin-6, glutathione S-transferase mu 2, and heat shock protein beta 7). In contrast to ET(+/+)eNOS(-/-) mice, eNOS(-/-) mice showed an elevated abundance of proteins responsible for sarcomere disassembly (e. g., cofilin-1 and cofilin-2). In ET(+/+)eNOS(-/-) mice, glycolysis was favored at the expense of fatty acid oxidation.
 Conclusion eNOS(-/-) mice developed diastolic dysfunction; this was rescued by ET-1 transgenic overexpression. This study furthermore suggests that cardiac ET-1 overexpression in case of eNOS deficiency causes specifically the regulation of proteins playing a role in oxidative stress, myocytes contractility, and energy metabolism.
KW  - cardiovascular diseases
KW  - endothelin
KW  - nitric oxide
Y1  - 2011
U6  - https://doi.org/10.1097/HJH.0b013e3283450770
SN  - 0263-6352
SN  - 1473-5598
VL  - 29
IS  - 5
SP  - 961
EP  - 970
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Hocher, Berthold
A1  - Heiden, S.
A1  - von Websky, Karoline
A1  - Rahnenführer, Jörg
A1  - Kalk, Philipp
A1  - Pfab, T.
T1  - Dual endothelin-converting enzyme/neutral endopeptidase blockade in rats with D-galactosamine-induced liver failure
JF  - European journal of medical research : official organ "Deutsche AIDS-Gesellschaft"
N2  - Secondary activation of the endothelin system is thought to be involved in toxic liver injury. This study tested the hypothesis that dual endothelin-converting enzyme / neutral endopeptidase blockade might: be able to attenuate acute toxic liver injury.
 Male Sprague-Dawley rats were implanted with subcutaneous minipumps to deliver the novel compound SLV338 (10 mg/kg*d) or vehicle. Four days later they received two intraperitoneal injections of D-galactosamine (1.3 g/kg each) or vehicle at an interval of 12 hours. The animals were sacrificed 48 hours after the first injection.
 Injection of D-galactosamine resulted in very severe liver injury, reflected by strongly elevated plasma liver enzymes, hepatic necrosis and inflammation, and a mortality rate of 42.9 %. SLV338 treatment did not show any significant effect on the extent of acute liver injury as judged from plasma parameters, hepatic histology and mortality. Plasma measurements of SLV338 confirmed adequate drug delivery. Plasma concentrations of big endothelin-1 and endothelin-1 were significantly elevated in animals with liver injury (5-fold and 62-fold, respectively). Plasma endothelin-1 was significantly correlated with several markers of liver injury. SLV338 completely prevented the rise of plasma big endothelin-1 (p<0.05) and markedly attenuated the rise of endothelin-1 (p = 0.055).
 In conclusion, dual endothelin-converting enzyme / neutral endopeptidase blockade by SLV338 did not significantly attenuate D-galactosamine-induced acute liver injury, although it largely prevented the activation of the endothelin system. An evaluation of SLV338 in a less severe model of liver injury would be of interest, since very severe intoxication might not be relevantly amenable to pharmacological interventions.
KW  - endothelin
KW  - endothelin-converting enzyme
KW  - neutral endopeptidase
KW  - D-galactosamine
KW  - acute liver failure
Y1  - 2011
SN  - 0949-2321
VL  - 16
IS  - 6
SP  - 275
EP  - 279
PB  - Med. Scientific Publ. Holzapfel
CY  - München
ER  -