精-甘-天冬-丝氨酸四肽对二磷酸腺苷诱导大鼠血小板活化的信号转导的影响

本工作在二磷酸腺苷（ＡＤＰ）活化的大鼠血小板上,观察精－甘－天冬－丝上肽（ＲＧＤＳ肽）对血小板聚集、蛋白磷酸化、蛋白激酶Ｃ和丝裂素活化蛋白激酶活性的影响。结果发现,５０μｍｏｌ／ＬＡＤＰ引起血小板聚集时,蛋白激酶Ｃ（ＰＫＣ０及丝裂经蛋白激酶（ＭＡＰＫ）活性增加,并引起９５和６６ｋＤ蛋白磷酸化。应用５０,１００和２００μｍｏｌ／ＬＲＧＤＳ肽与基共同孵育,呈浓度依赖地抑制ＡＤＰ引起的血小板聚集和对ＰＫ

Effect of Arg-Gly-Asp-Ser (RGDS) peptide on ADP-induced signal transduction of activated rat platelet

The purpose of this work was to investigate the effect of Arg-Gly-Asp-Ser (RGDS) peptide on platelet aggregation, protein phosphorylation, protein kinase C (PKC) and mitogen-activated protein kinase (MAPK) activity during platelet activation. Experiments were performed on ADP activated rat platelets in vivo. Results showed that 50 mumol/L ADP, in addition to inducing platelet aggregation, obviously enhanced not only PKC and MAPK activities but also 95 and 66 kD protein phosphorylation. When platelets and ADP were incubated together with 50, 100, 200 mumol/L RGDS peptide it was found that the latter markedly inhibited ADP activated platelet aggregation and activation of PKC and MAPK, both in a concentration-dependently manner. RGDS peptide also inhibited 95 and 66 kD protein phosphorylation concentration-dependently and went positively with its activation of PKC and MAPK. The above result suggested that the antithrombotic effect of RGDS peptide was probably mediated through its effect on intracellular signal transduction in the ADP activation of platelets.