Comparison of the inhibitory effects of docosahexaenoic acid (DHA) on U46619- and phenylephrine-induced contractions in guinea-pig aorta.
Inhibitory effects of docosahexaenoic acid (DHA) on the muscle contractions induced by U46619, a thromboxane A2 (TXA2) mimetic, and phenylephrine were compared in guinea-pig aorta. In de-endothelialized guinea-pig aortic ring preparations, DHA at 10 microM strongly inhibited a sustained contraction produced by U46619 (3-100 nM) whereas it did not exhibit an appreciable effect on phenylephrine (3-10 microM)-induced contraction. The present findings indicate that DHA inhibits more selectively TXA2 receptor (TP receptor)-mediated vascular contraction than alpha-adrenoceptor-mediated response. Selective inhibition by DHA of TP receptor-mediated contraction of blood vessels seems underlie in part the mechanisms by which this polyunsaturated fatty acid exerts its circulatory-protective effects.
Department of Pharmacology, Toho University School of Pharmaceutical Sciences, Chiba, Japan.
Kazuoki
K
Otsuka
Yoshio
Y
Tanaka
Hikaru
H
Tanaka
Katsuo
K
Koike
Koki
K
Shigenobu
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects* / Q000502:physiology; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D010656:Phenylephrine / Q000037:antagonists & inhibitors* / Q000494:pharmacology
D010656:Phenylephrine; D004281:Docosahexaenoic Acids; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid