5-Hydroxytryptamine can mediate endothelium-dependent relaxation of coronary arteries.
5-Hydroxytryptamine can mediate endothelium-dependent relaxation of coronary arteries.
复制标题
5-羟色胺可以介导冠状动脉的内皮依赖性舒张。
DOI：
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发表时间：
1983
影响因子：
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通讯作者：
P. Vanhoutte
中科院分区：
文献类型：
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作者：
R. Cohen;J. Shepherd;P. Vanhoutte
5-羟色胺引起离体犬冠状动脉环收缩。这些收缩在没有内皮细胞的情况下更大，而苯肾上腺素，氯化钾和前列腺素F2 α引起的收缩则没有。当用前列腺素F2 α收缩冠状动脉时，5-羟色胺引起某些有内皮的环舒张，但在所有无内皮的环中仅进一步收缩。内皮细胞介导的5-羟色胺的抑制作用不受单胺氧化酶或环氧合酶阻断的影响。在有内皮的环中，聚集的血小板释放5-羟色胺和血栓素A2，引起舒张。5-羟色胺和聚集的血小板引起的舒张作用被麦角新碱拮抗，但不被酮色林。这些观察结果表明，对5-羟色胺的反应是对冠状动脉平滑肌的直接收缩作用和内皮介导的抑制作用的净结果。在某些血管中，对聚集血小板的内皮依赖性抑制反应可能部分由释放的5-羟色胺介导。内皮细胞上的肾上腺素能受体可能是与介导平滑肌细胞收缩的受体不同的亚型。
5-Hydroxytryptamine caused contractions of isolated canine coronary artery rings. These contractions were larger in the absence of the endothelium, whereas those caused by phenylephrine, potassium chloride, and prostaglandin F2 alpha were not. When coronary arteries were contracted with prostaglandin F2 alpha, 5-hydroxytryptamine caused relaxation in some rings with endothelium but only further contraction in all rings without endothelium. The inhibitory action of 5-hydroxytryptamine mediated by the endothelium was unaffected by blockade of monoamine oxidase or cyclooxygenase. In rings with endothelium, aggregating platelets, which released 5-hydroxytryptamine and thromboxane A2, caused relaxation. The relaxations caused by 5-hydroxytryptamine and aggregating platelets were antagonized by methysergide but not by ketanserin. These observations suggest that the response to 5-hydroxytryptamine is the net result of a direct contractile action on coronary smooth muscle and an inhibitory action mediated by the endothelium. In some vessels the endothelium-dependent inhibitory responses to aggregating platelets may be mediated in part by released 5-hydroxytryptamine. The serotonergic receptors on endothelial cells may be of a different subtype than those mediating contractions of the smooth muscle cells.