Effect of verapamil on responses to endothelin-1 in aortic rings from streptozotocin-induced diabetic rats.
In this study, we investigated the constrictor responsiveness to endothelin-1 (ET-1, 10-30 n m) of aortic rings (under 1 g resting tension in Krebs-Bicarbonate solution) from 8-weeks streptozotocin (STZ, 65 mg kg-1, i.p)-induced diabetic rats and vehicle-treated control rats. The maximum ET-1-induced contraction of the aorta in diabetic rats was increased by 150%, but the EC50 of ET-1 remained unchanged. Although in both groups, verapamil reduced the constrictor responses to ET-1 (diabetic group P<0.001, control group P<0.05), there were not any significant differences between PD2 values. These results suggest that verapamil inhibits ET-1-induced Ca2+ entry through the L-type channel and this effect did not change in diabetes mellitus.
Murat
N
N
Department of Pharmacology, Dokuz Eyluöl University Medical Faculty, Izmir, Balcova, 35340, Turkey.
Kalkan
S
S
Gidener
S
S
D000818:Animals; D001013:Aorta, Thoracic; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000503:physiopathology*; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000494:pharmacology*; D066298:In Vitro Techniques; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin; D014661:Vasoconstriction / Q000187:drug effects*; D014700:Verapamil / Q000494:pharmacology*
D019332:Endothelin-1; D013311:Streptozocin; D014700:Verapamil