地塞米松影响血小板聚集、释放机理的探讨

THE MECHANISM OF DEXAMETHASONE EFFECT ON RABBIT PLATELET AGGREGATION AND RELEASE

通过对离体兔血小板研究发现:地塞米松(Dex)能抑制胶原诱导的血小板聚集、释放和血栓素A_2(TXA_2)生成等反应,而对花生四烯酸(AA)诱导的上述反应则无明显影响。本研究还发现,Dex能抑制血小板的磷脂酸A_2(PLA_2)活性,细胞外Ca^(2+)可部分拮抗Dex的上述作用,表明Dex的作用可能与其限制细胞外Ca^(2+)进入细胞内有关。Dex对血小板钙调素(CaM)和腺苷酸环化酶(AC)活性,以及对cAMP和cGMP的生成均无明显影响。

The effect of dexamethason ( Dex ) on the rabbit platelet aggregation and release was studided. The results were showed that the platelet aggregation and release induced by collagen were inhibited markedly by Dex, TXA2 production of platelets also reduced, but the platelet activation induced by AA was not affected by Dex. The results were further showed that the PLA2 activity was depressed by Dex, and the action of Dex can be antagonized partly by increase of extracellular Ca2+, it suggests that Dex inhibited the activity of PLA2 with the reduction of Ca2+ inflow into cell. The activity of CaM and AC, the production of cAMP and cGMP were not affected by Dex.