Kishi Y, Ashikaga T, Numano F
Third Department of Medicine, Tokyo Medical and Dental University, Japan.
Am Heart J. 1992 Feb;123(2):291-7. doi: 10.1016/0002-8703(92)90637-b.
We tested whether alteration of platelet sensitivity to prostacyclin (PGI2) is involved in the activation of platelets induced by exercise in patients with stable angina. Twenty patients and 20 control subjects underwent treadmill testing. Blood samples were obtained before and immediately after exercise for plasma thromboxane B2 (TXB2) and 6-keto-PGF1 alpha (6kP) assays and platelet aggregation studies. Dose-response curves for platelet aggregation to collagen were obtained in the presence and absence of 1 nmol/L PGI2 to quantify the antiaggregation effects of PGI2. At rest, platelet aggregation by collagen was enhanced in the patients. However, platelets were more sensitive to exogenous PGI2, apparently associated with lower plasma 6kP levels in the patients. After exercise, plasma TXB2 levels increased in the patients but not in the control subjects. Plasma 6kP levels remained unchanged and platelet sensitivity to PGI2 decreased in the patients whereas these values increased in the control subjects. The exercise-induced changes in platelet sensitivity to PGI2 correlated with those of platelet adenylate cyclase activity in response to 1 nmol/L PGI2 (r = 0.787, p less than 0.01). Thus impaired sensitivity of platelets to PGI2, in addition to the reduced response of prostanoid secretion, might be relevant to the platelet activation associated with exercise in patients with stable angina.
我们测试了血小板对前列环素（PGI2）敏感性的改变是否参与稳定型心绞痛患者运动诱导的血小板激活过程。20例患者和20名对照者进行了平板运动试验。在运动前和运动后即刻采集血样，用于检测血浆血栓素B2（TXB2）和6-酮-前列腺素F1α（6kP），并进行血小板聚集研究。在存在和不存在1 nmol/L PGI2的情况下，获得血小板对胶原聚集的剂量-反应曲线，以量化PGI2的抗聚集作用。静息时，患者胶原诱导的血小板聚集增强。然而，患者血小板对外源性PGI2更敏感，这显然与患者较低的血浆6kP水平有关。运动后，患者血浆TXB2水平升高，而对照者未升高。患者血浆6kP水平保持不变，血小板对PGI2的敏感性降低，而对照者这些值升高。运动诱导的血小板对PGI2敏感性变化与血小板腺苷酸环化酶对1 nmol/L PGI2反应的变化相关（r = 0.787，p < 0.01）。因此，除了类前列腺素分泌反应降低外，血小板对PGI2的敏感性受损可能与稳定型心绞痛患者运动相关的血小板激活有关。
