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, the angiotensin II-induced contractions were increased to 101%, 109%, 114%, 109% and 98%, respectively. The optimum preincubation time for the maximum effect of 12-HETE was 5 min. Under these conditions, 12-HETE increased dose dependently the contraction induced by 10 nM angiotensin II, and the concentration needed for the maximum effect was 30 nM, which increased contraction to 118% compared to the control angiotensin II-induced contraction. We demonstrated clearly that 12-HETE directly potentiates the angiotensin II-induced contraction.
Takai
S
S
Department of Pharmacology, Osaka Medical College, Takatsuki, Japan. pha010@art.osaka-med.ac.jp
Jin
D
D
Hara
K
K
Takami
H
H
Fujita
T
T
Miyazaki
M
M
D000804:Angiotensin II / Q000819:agonists*; D000818:Animals; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
D006893:Hydroxyeicosatetraenoic Acids; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; D009638:Norepinephrine