钩藤碱对血小板聚集和血栓形成的影响

钩藤碱(Rhy)明显抑制AA,胶原及ADP诱导的大鼠血小板聚集。Rhy不影响血小利用外源性AA合成TXA_2,但抑制胶原诱导的TXA_2生成;在抗血小板聚集有效剂量时,对PGI_2的生成无影响。Rhy有显著降低血栓形成诱导剂ADP及胶原加肾上腺素静脉注射所致小鼠死亡率。

EFFECT OF RHYNCHOPHYLLINE ON PLATELET AGGREGATION AND EXPERIMENTAL THROMBOSIS

Rhynchophylline (Rhy)produced a potent inhibition of rat platelet aggregatin in ex vivo. TXA_2 generation in platelet rich plasma from rats treated with Rhy obviously decreased in the collagen-induced group, but was not altered in the AA-induced group. These results suggest that Rhy suppressed the release of AA from platelet phospholipids stimulated by collagen, and this may be one of the mechanisms related to its action on platelet aggregation. Pretreatment with ASA, but not Rhy, reduced plasma PGI_2 in rats. In the in vitro system, the PGI_2 synthesis in rat aorta was shown to be inhibited by ASA but was not by Rhy. Rhy significantly reduced the number of mice died due to thrombosis by platelet aggregates. ASA prevented collagen plus adrenaline induced thrombotic death while Rhy prevented both ADP and collagen plus adrenaline induced thrombotic death.