- 作者: George Hsiao; Ming-Yi Shen; Duen-Suey Chou; Chien-Huang Lin; Tzeng-Fu Chen; Joen-Rong Sheu
- 作者服務機構: Graduate Institute of Pharmacology and Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan
- 中文摘要: --
- 英文摘要: Magnesium sulfate is widely used to prevent seizures inpregnant women with hypertension. The aim of thisstudy was to examine the inhibitory mechanisms ofmagnesium sulfate in platelet aggregation in vitro.In thisstudy, magnesium sulfate concentration-dependently(0.6-3.0 mM inhibited platelet aggregation in humanplatelets stimulated by agonists.Magnesium sulfate(1.5and 3.0 mM)also concentration-dependently inhibitedphosphoinositide breakdown and intracellular Ca+2 mo-bilization in human platelets stimulated by thrombin.Rapid phosphorylation of a platelet protein of Mr 47,000(P47), a marker of protein kinase C activation, was trig-gered by phorbol-12-13-dibutyrate(PDBu,50 n Ilk.Thisphosphorylation was markedly inhibited by magnesiumsulfate(3.0 mM.Magnesium sulfate(1.5 and3.0 m M)further inhibited PDBu-stimulated platelet aggregation inhuman platelets. The thrombin-evoked increase in pHiwas markedly inhibited in the presence of magnesiumsulfate (3.0 mM).In conclusion,these results indicatethat the antiplatelet activity of magnesium sulfate maybe involved in the following two pathways:(1)Magne-sium sulfate may inhibit the activation of protein kinaseC, followed by inhibition of phosphoinositide breakdownand intracellular Ca+2 mobilization,thereby leading toinhibition of the phosphorylation of P47.(2)On the otherhand,magnesium sulfate inhibits the Na+/H+ exchanger,leading to reduced intracellular Ca +2 mobilization,andultimately to inhibition of platelet aggregation and theATP-release reaction.
- 中文關鍵字: --
- 英文關鍵字: --