PROSTAGLANDIN-INDEPENDENT DECREASE OF SHEEP URETER CONTRACTILITY INDUCED BY BRADYKININ

The machanisms that mediate the actions of bradykinin on ureteral moti lity are poorly defined and mediation via prostaglandins has not been examined. Therefore, the effects of bradykinin on contractility and th e possible mediator role of prostaglandins have been investigated in s heep ureter. At the concentrations of 10(-8), 10(-7) and 10(-6)M, brad ykinin elicited marked reductions in contractile force. When ureteral strips were treated separately with 10(-6)M indomethacin, 2x10(-6)M so dium salicylate and 10(-5)M aspirin, each drug produced a significant decrease in contractile force. In strips in which prostaglandin synthe sis was inhibited by the above concentrations of indomethacin, sodium salicylate and aspirin, 10(-7)M bradykinin significantly decreased the contractility. From these data, we concluded that in ureter bradykini n decreases contractility via a mechanism not involving prostaglandin generation.