Ertuna E.Yasa M.2019-10-272019-10-2720051015-39181015-3918https://hdl.handle.net/11454/21859The purpose of this study was to investigate the effect of glibenclamide, a selective ATP-sensitive K+ (KATP) channel blocker, on agonist-induced contractions in isolated rat aortic rings. The possible involvement of endothelium in glibenclamide-induced response was also investigated. The concentration-response curves of prostaglandin F 2?(PGF2?; 0.1 nM-30 µM), serotonin (5-hydroxytryptamine, 5-HT; 1 nM-30 µM) and phenylephrine (1 nM-30 µM) were obtained in the absence or presence of glibenclamide (1, 3 or 10 µM). Maximum agonist-induced contractions in the presence of glibenclamide 1, 3 and 10 µM were decreased by 30±5, 64±3 and 86±2 percent for PGF2? and 41±11, 50±11 and 65±5 percent for 5-HT respectively. Phenylephrine-induced contractions remained unaltered by glibenclamide 10 µM. The inhibitory effect of glibenclamide (10 µM) on PGF2?- or 5-HT-induced contractions were attenuated upon N ?-nitro-L-arginin (L-NNA; 100 µM) plus indomethacin (10 µM) incubation. The inhibitory effect of glibenclamide on PGF 2?-induced contractions was also assessed in endothelium-denuded arteries and the inhibitory effect of glibenclamide was greater in endothelium-denuded arteries than in endothelium-intact arteries pretreated with L-NNA plus indomethacin (64±4% versus 46±10%, respectively). These results suggest that glibenclamide could act through multiple sites in either endothelium or the underlying arterial smooth muscle and thus serve as a non-selective muscle relaxant at high concentration.eninfo:eu-repo/semantics/closedAccessEndotheliumGlibenclamideProstaglandin F2? serotoninRat aortaArticle342119128Q4