不同剂量乌司他丁对常温体外循环兔血小板的影响

目的 探讨不同剂量乌司他丁对常温体外循环(CPB)兔血小板数量和功能的影响.方法 健康大耳白兔50只,月龄5～6月,体重2.3～3.0 kg,随机分为5组(n=10),不同剂量乌司他丁组(U_(1～4)组)于CPB前即刻分别静脉注射乌司他丁1×10~4、3×10~4、5×10~4、10×10~4 U/kg,对照组(C组)给予等容量生理盐水.于CPB前即刻(T_0)、CPB结束即刻(T_1)、结束后1 h(T_2)、2 h(T_3)、3 h(T_4)时记录MAP、HR和红细胞压积(Hct),同时取血样,行血小板计数,测定血小板粘附率(PAR)和血小板膜糖蛋白Ⅰ b(Gp Ⅰ b)、GpⅡb和GpⅢa受体分子数.结果 与C组比较,U_2组、U_3组和U_4组Gp Ⅰ b、GpⅡ b、GpⅢa受体分子数升高,U_4组PAR升高(P<0.05).与U_1组比较,U_3组Gp Ⅰ b受体分子数升高,U_4组Gp Ⅰ b、GpⅡb受体分子数升高(P<0.05).与U_2组比较,U组Gp Ⅰ b、Gp Ⅱ b受体分子数升高(P<0.05).各组间血小板计数比较差异无统计学意义(P>0.05).结论 CPB前应用乌司他丁3×10~4～5×10~4 U/kg可呈剂量依赖性地抑制兔血小板膜糖蛋白受体分解,剂量达10×10~4 U/kg时可提高血小板的粘附功能.

Effects of different doses of ulinastatin on platelets during normothermic cardiopulmonary bypass in rabbits

Objective To investigate the effects of different doses of ulinastatin on platelet counts and function after normothermic cardiopulmonary bypass (CPB) in rabbits. Methods Fifty lung-ear white rabbits aged 5-6 months weighing 2.3-3.0 kg were randomly assigned to one of 5 groups (n = 10 each) : control group (group C) and4 ulinastatin groups (group U~1, U_2,U_3,U_4). The rabbits received ulinastatin 1×10~4, 3×10~4, 5×10~4 and 10×10~4 U/kg before CPB in group U~1, U_2, U_3 and U_4 respectively while equal volume of normal saline was given instead of ulinastatin in group C. All rabbits underwent CPB for 30 min at perfusion flow of 72-120 ml·kg~(-1) ·min~(-1). The rectal temperature was maintained at 36.5-37.5℃. Hemodynamic parameters were recorded and blood platelet count, platelet adhesion rate and platelet membrane glycopretein Gp Ⅰ b, Gp Ⅱ b, Gp Ⅲ a receptors were determined before CPB (baseline), at termination of CPB and at 1, 2 and 3 h after CPB. Results The platelet counts were significantly decreased after CPB in all 5 groups (P< 0.05), but there was no significant difference among the 5 groups. The platelet adhesion rates were significantly decreased after CPB as compared with the baseline value before CPB in all 5 groups but the platelet adhesion rates were significantly higher after CPB in group U_4 than in group C. The number of molecules of Gp Ⅰ b, Gp Ⅱ b and Gp Ⅲ a receptors was significantly decreased after CPB in all 5 groups. The number of molecules of Gp Ⅰ b, Gp Ⅱ b and Gp Ⅲ a receptors after CPB was significantly higher in group U_2, U_3 and U_4 than in group C, and there was no significant difference between group U_3 and U_4 . Conclusion Ulinastatin 3×10~4-5×10~4 U/kg administered before CPB can inhibit breakdown of platelet membrane glycoprotein receptors. Ulinastatin 10×10~4 U/kg can preserve the platelet adhesion function.