ATP release caused by bradykinin, substance P and histamine from intact and cultured smooth muscles of guinea-pig vas deferens

Abstract

Histamine (60 μM) produced ATP release from segments of guinea-pig vas deferens which was blocked by pyrilamine and triprolidine, H₁-blockers, but not by ranitidine, an H₂-blocker. The evoked-release was inhibited by the mitochondrial inhibitors, carbonyl cyanide-m-chlorophenylhydrazone (CCCP) and oligomycin. Bradykinin (BK) and substance P (SP) also caused substantial and moderate release of ATP, respectively. The BK-evoked release of ATP was inhibited by HOE140, a B₂-antagonist, but not by [Des-Arg¹⁰] HOE140, a B₁-antagonist. On the other hand, VIP, angiotensin II (AII) and cholecystokinin-octapeptide (CCK-8) failed to elicit a measurable release of ATP. Histamine and BK also enhanced the release of ATP from superfused cultured smooth muscle cells. These results suggest that ATP may be released as an autacoid from the smooth muscles in the presence of these chemical mediators.