Gleerup G, Winther K
Department of Clinical Chemistry, Frederiksberg Hospital, Denmark.
Am J Med. 1989 Apr 17;86(4A):127-9. doi: 10.1016/0002-9343(89)90207-6.
The effects of non-selective beta-blockade (timolol, 5 mg twice daily) and calcium antagonism (isradipine, 2.5 mg twice daily) on heart rate, blood pressure, platelet aggregation, fibrinolytic activity, and platelet cyclic adenosine monophosphate content were investigated in 10 patients with mild hypertension in a randomized, placebo-controlled, double-blind study. Each patient served as his or her own control, taking each drug in turn for two weeks. Both drugs lowered blood pressure to the same degree. During timolol treatment, however, platelet aggregation increased whereas isradipine resulted in a shortening of the euglobulin clot lysis time (p less than 0.05), indicating increased fibrinolytic activity. Platelet aggregation and fibrinolytic activity are modified by cyclic adenosine monophosphate. Since beta-adrenoceptors are present on platelets and endothelial cells, the differences in platelet behavior and fibrinolytic activity may reflect a decreased cyclic adenosine monophosphate production caused by non-selective beta-adrenoceptor blockade.
在一项随机、安慰剂对照、双盲研究中，对10例轻度高血压患者研究了非选择性β受体阻滞剂（噻吗洛尔，每日2次，每次5毫克）和钙拮抗剂（伊拉地平，每日2次，每次2.5毫克）对心率、血压、血小板聚集、纤溶活性和血小板环磷酸腺苷含量的影响。每位患者均作为自身对照，依次服用每种药物两周。两种药物降低血压的程度相同。然而，在噻吗洛尔治疗期间，血小板聚集增加，而伊拉地平导致优球蛋白凝块溶解时间缩短（p<0.05），表明纤溶活性增加。血小板聚集和纤溶活性受环磷酸腺苷调节。由于血小板和内皮细胞上存在β肾上腺素能受体，血小板行为和纤溶活性的差异可能反映了非选择性β肾上腺素能受体阻断导致的环磷酸腺苷生成减少。
