P-1,P-4-DIADENOSINE 5' TETRAPHOSPHATE INDUCES NITRIC-OXIDE RELEASE FROM BOVINE AORTIC ENDOTHELIAL-CELLS

Since the infusion of P-1,P-4-diadenosine 5' tetraphosphate (Ap4A) int o animal models induces vasodilation [1,2], the present study was perf ormed to determine whether Ap4A induces the release of nitric oxide (N O) from endothelial cells. Ap4A induced NO release was 4.2-fold greate r than the amount of NO released under basal condition. Ap4A induced N O release was inhibited by N-G-nitro-L-arginine (L-NNA) and this inhib ition was reversed by L-Arg. In addition, EGTA inhibits Ap4A induced N O release. These data are consistent with Ap4A inducing the release of NO from endothelial cells through the activation of endothelial nitri c oxide synthase. (C) 1998 Federation of European Biochemical Societie s.