Endothelium is required for 12-hydroperoxyeicosatetraenoic acid-induced vasoconstriction

The pharmacological effects of 12-hydroperoxyeicosatetraenoic acid (12-HPETE) were examined using isolated canine basilar artery segments and isometric tension recording. 12-HPETE produced transient contraction of the artery segment while arachidonic acid or 12-hydroxyeicosatetraenoic acid (12-HETE) had a much lower potency. 12-HPETE-induced contraction which showed a requirement of a functional endothelium and a rapid insensitivity to re-administered 12-HPETE, was completely inhibited by the Potassium Channel blocker, glibenclamide. Other hydroperoxides did cross-desensitize the 12-HPETE-induced contraction, however, arachidonic acid or 12-HETE did not affect markedly. Here, we present that 12-HPETE is involved in the regulation of vascular tension via its effects on the endothelium.