Fujimura A, Ohashi K, Ebihara A
Department of Clinical Pharmacology, Jichi Medical School, Tochigi, Japan.
Life Sci. 1992;50(14):1043-7. doi: 10.1016/0024-3205(92)90099-b.
Platelet aggregation is known to show a morning rise. The present study was undertaken to examine whether platelet aggregation and adhesion show a peak in the afternoon. Platelet aggregation stimulated by 4 microM of adenosine diphosphate, 1 micrograms/ml of collagen, 4 microM of epinephrine and 0.5 mM of arachidonic acid, and platelet adhesion determined by platelet retention on a glass bead column were measured for a period of 28-hour with an interval of 4 hours in 6 healthy subjects. Platelet aggregation in response to 4 different aggregating agents showed a bimodal daily variation with peaks in the morning and in the afternoon. However platelet adhesion only showed a peak in the morning. Previous studies have demonstrated the increases in the onset of acute myocardial infarction (MI) in the morning and afternoon periods. As enhanced platelet aggregation is involved in the development of acute MI, the present study suggests that the rise in platelet aggregation contributes to the increase in acute MI in the morning and in the afternoon. The present study suggests that the enhancement of platelet adhesion, which might be involved in thromboembolic events, may be another triggering factor for the onset of acute MI.
已知血小板聚集呈早晨升高的趋势。本研究旨在探讨血小板聚集和黏附是否在下午出现峰值。在6名健康受试者中，每隔4小时测量一次，持续28小时，测定4微摩尔二磷酸腺苷、1微克/毫升胶原蛋白、4微摩尔肾上腺素和0.5毫摩尔花生四烯酸刺激后的血小板聚集情况，以及通过玻璃珠柱上的血小板滞留测定的血小板黏附情况。对4种不同聚集剂的血小板聚集反应呈现出每日双峰变化，峰值出现在上午和下午。然而，血小板黏附仅在上午出现峰值。先前的研究已证实急性心肌梗死（MI）发病在上午和下午时段有所增加。由于增强的血小板聚集参与急性心肌梗死的发展，本研究表明血小板聚集的升高促成了上午和下午急性心肌梗死的增加。本研究表明，可能参与血栓栓塞事件的血小板黏附增强，可能是急性心肌梗死发病的另一个触发因素。
