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 an d isometric tension recording. 12-HPETE produced transient contraction of the artery segment while arachidonic acid or 12-hydroxyeicosatetra enoic acid (12-HETE) had a much lower potency. 12-HPETE-induced contra ction which showed a requirement of a functional endothelium and a rap id 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, arac hidonic acid or 12-HETE did not affect markedly. Here, we present that 12-HPETE is involved in the regulation of vascular tension via its ef fects on the endothelium. (C) 1998 Elsevier Science B.V.