Gleerup G, Winther K
Department of Cardiology, Glostrup Hospital, Copenhagen, Denmark.
Angiology. 1995 Aug;46(8):715-8. doi: 10.1177/000331979504600810.
Twelve healthy male volunteers, mean age twenty-five, range twenty-one to thirty years, and 12 healthy middle-aged male volunteers mean age fifty-eight, range forty-four to seventy-two years, were tested regarding platelet aggregation induced by adenosine diphosphate and fibrinolytic activity, estimated as euglobulin clot lysis time (ECLT), tissue plasminogen activator (t-PA), and the fast-acting inhibitor against t-PA normally referred to as (PAI-1). Platelet aggregation increased significantly in the middle-aged group as compared with the young, as shown by a decrease in ADP thresholds for irreversible aggregation (P < 0.01). In healthy young volunteers, vigorous cycling exercise by itself caused platelet aggregability to decrease (P < 0.05). Such changes were not observed in the elderly. Fibrinolytic activity decreased significantly in the middle-aged group as shown by a prolongation of the ECLT (P < 0.01) and PAI-1, although not significantly, increased by approximately 100%, whereas t-PA significantly increased in the middle-aged group (P < 0.01). The present results suggest that increasing age is associated with not only increased platelet aggregability but also decreased fibrinolytic activity.
12名健康男性志愿者，平均年龄25岁，年龄范围在21至30岁之间，以及12名健康中年男性志愿者，平均年龄58岁，年龄范围在44至72岁之间，接受了关于二磷酸腺苷诱导的血小板聚集和纤溶活性的测试，纤溶活性通过优球蛋白凝块溶解时间（ECLT）、组织纤溶酶原激活物（t-PA）以及通常称为（PAI-1）的t-PA快速作用抑制剂来评估。与年轻人相比，中年组的血小板聚集显著增加，表现为不可逆聚集的ADP阈值降低（P < 0.01）。在健康年轻志愿者中，剧烈的自行车运动本身会导致血小板聚集性降低（P < 0.05）。在老年人中未观察到此类变化。中年组的纤溶活性显著降低，表现为ECLT延长（P < 0.01），PAI-1虽未显著升高，但增加了约100%，而中年组的t-PA显著升高（P < 0.01）。目前的结果表明，年龄增长不仅与血小板聚集性增加有关，还与纤溶活性降低有关。
