Popis: |
The effect of endothelin-1 (ET-1) on vasoconstrictor responses of the endothelium-denuded perfused rabbit ear artery to 5-hydroxytryptamine (5-HT), histamine, and vasopressin (VP) was studied. In low concentrations with no vasoconstrictor action (0.1 and 0.3 nM), and in a concentration that increased the perfusion pressure by 70 mm Hg (1 nM), ET-1 significantly enhanced responses to the agonists studied; this enhancement was apparently mediated by an increased influx of extracellular calcium through voltage-operated channels, as it was abolished by the calcium channel antagonist nicardipine (10 nM) |