文章基本信息

标题：Effect of Equol on Vasocontractions in Rat Carotid Arteries Treated with High Insulin
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作者：Takayuki Matsumoto ; Keisuke Takayanagi ; Shota Kobayashi 等
期刊名称：Biological and Pharmaceutical Bulletin
印刷版ISSN：0918-6158
电子版ISSN：1347-5215
出版年度：2019
卷号：42
期号：6
页码：1048-1053
DOI：10.1248/bpb.b19-00051
出版社：The Pharmaceutical Society of Japan
摘要：Previous research has indicated that high insulin affects vascular function. Equol is an active metabolite of daidzein, an isoflavone produced from soy by intestinal microbial flora, with beneficial effects on the vascular system. This study investigated whether equol was beneficial for vascular function under high insulin conditions. Using organ culture techniques, rat carotid arteries were treated for 23 ± 1 h with a vehicle, high insulin (100 nM), or equol (100 µM) plus high insulin (100 nM). Vascular isometric forces were measured by the organ bath technique. In each endothelium-intact ring, the contractions induced by high-K+, noradrenaline, or by serotonin (5-HT) were similar for the vehicle, insulin, and equol + insulin treatments. Contractions induced by a selective 5-HT2A receptor agonist (TCB2) increased with insulin treatment ( vs. vehicle), but less so with equol + insulin. Under basal conditions, a selective 5-HT2B receptor agonist (BW723C86) did not induce contraction; following precontraction by a thromboxane analog, it induced contraction but not relaxation. These responses were similar across the three treatments. Acetylcholine-induced relaxations were also similar for the three treatments. In the endothelium-denuded preparations, 5-HT-induced contraction was augmented with insulin treatment ( vs. vehicle) but less so by equol + insulin treatment. These differences in 5-HT-induced contractions were eliminated by iberiotoxin, a large-conductance calcium-activated K+ channel (BKCa) inhibitor. These results suggest that equol exerts a preventive effect on the enhancement of 5-HT-induced contraction by high insulin (possibly mediated by the 5-HT2A receptor), and that these effects may be attributed to the activation of BKCa channels in vascular smooth muscle.
关键词：carotid artery;equol;insulin;serotonin;vasocontraction