R. Schwinger, C. Schulz, K. Brixius
Aug 1, 1996
Citations
0
Influential Citations
1
Citations
Quality indicators
Journal
Naunyn-Schmiedeberg's Archives of Pharmacology
Abstract
Background: The present study aimed to characterize the effects of epinine, the active metabolite of ibopamine on tension development in human renal arteries.Methods and results: Experiments were performed on isolated human renal arteries rings obtained during surgery due to kidney tumors (n = 12). Epinine concentration-dependently relaxed isolated precontracted (PGF2α) human renal artery rings (P < 0.05) in the presence of phentolamine, as effectively (epinine − 30 +/− 4 mN, dopamine − 31 +/− 5 mN) and with the same potency as dopamine (epinine EC50 0.7 μmol/l (0.4−1.2 μmol/l), dopamine 0.5 μmol/l (0.2−1.7 μmol/l)). This effect was antagonized by the specific D1-receptor-antagonist SCH 23390. Effective β-adrenoceptor antagonistic concentrations of propranolol did not affect epinine-induced vasorelaxation. In the absence of α-and β-adrenoceptor-antagonists the potency of epinine to contract renal artery rings was significantly higher compared to dopamine indicating a higher affinity of epinine to α-adrenoceptors.Conclusion: The present study provides evidence for direct vasodilatory effects of epinine via activation of D1-receptors on human renal arteries.