12-HYDROXYEICOSATETRAENOIC ACID DIRECTLY POTENTIATES ANGIOTENSIN-II-INDUCED VASCULAR CONTRACTION

We studied whether 12-hydroxyeicosatetraenoic acid (HETE) affected the angiotensin II-induced contractile response in isolated hamster aorta . After preincubation with 10 nM 12-HETE for 1, 3, 5, 10 and 30 min, t he angiotensin II-induced contractions were increased to 101%, 109%, 1 14%, 109% and 98%, respectively. The optimum preincubation time for th e maximum effect of 12-HETE was 5 min. Under these conditions, 12-METE increased dose dependently the contraction induced by 10 nM angiotens in II, and the concentration needed for the maximum effect was 30 nM, which increased contraction to 118% compared to the control angiotensi n II-induced contraction. We demonstrated clearly that 12-HETE directl y potentiates the angiotensin II-induced contraction. (C) 1998 Elsevie r Science B.V. All rights reserved.