Aggregating human platelets cause direct contraction and endothelium-dependent relaxation of isolated canine coronary arteries. Role of serotonin, thromboxane A2, and adenine nucleotides.
Aggregating human platelets cause direct contraction and endothelium-dependent relaxation of isolated canine coronary arteries. Role of serotonin, thromboxane A2, and adenine nucleotides.
复制标题
聚集的人血小板导致离体犬冠状动脉的直接收缩和内皮依赖性舒张。
DOI：
10.1172/jci112606
复制
发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Vanhoutte,PM
中科院分区：
文献类型：
--
作者：
Houston,DS;Shepherd,JT;Vanhoutte,PM
聚集的人血小板收缩无内皮的犬冠状动脉环，但舒张内皮完整的环。我们进行了实验，以确定从血小板释放的物质负责这些影响。通过用血栓素合成酶抑制剂dazoxiben处理血小板或用血栓素受体拮抗剂SQ 29548处理血管，可减少无内皮环的收缩。甲硫氨酸能拮抗剂，也减少血小板诱导的收缩。甲硫替平与达唑昔苯或SQ 29548的组合引起进一步的抑制。在由前列腺素F2 α引起的收缩过程中对血小板的内皮依赖性舒张几乎被ADP和ATP清除剂腺苷三磷酸双磷酸酶消除。它不被甲硫氨酸抑制，甲硫氨酸拮抗内皮依赖性舒张5-羟色胺。因此，血清素和血栓素A2都有助于通过聚集人血小板直接激活冠状动脉平滑肌，而腺嘌呤核苷酸是内皮依赖性舒张的主要介质。
Aggregating human platelets contract isolated rings of canine coronary artery without endothelium, but relax rings with intact endothelium. We performed experiments to identify the substances released from platelets responsible for these effects. The contraction in rings without endothelium was reduced by treating the platelets with thromboxane synthetase inhibitor, dazoxiben, or treating the vessels with the thromboxane-receptor antagonist, SQ 29548. The serotonergic antagonist, methiothepin, also reduced the platelet-induced contraction. The combination of methiothepin plus dazoxiben or SQ 29548 caused a further inhibition. The endothelium-dependent relaxation to platelets during contractions evoked by prostaglandin F2 alpha was nearly abolished by the ADP- and ATP-scavenger, apyrase. It was not inhibited by methiothepin, which antagonizes endothelium-dependent relaxations to serotonin. Thus, both serotonin and thromboxane A2 contribute to the direct activation of coronary smooth muscle by aggregating human platelets, whereas adenine nucleotides are the principal mediators of the endothelium-dependent relaxation.