大剂量乌司他丁在兔常温体外循环中对血小板的影响

目的观察兔常温体外循环（CPB）前应用大剂量乌司他丁对血小板数量和功能的影响。材料和方法20只大耳白兔随机分成2组：乌司他丁组（U组，n=10）和对照组（C组，n=10）。U组在CPB前给予乌司他丁10×10^4U／kg，C组给予等量生理盐水，CPB30min，流量为180—300ml／min，肛温维持在36．5～37．5℃。分别记录CPB前、停机、停机后1h、2h和3h的血流动力学指标，测定血小板计数、血小板粘附率（PAR）和血小板膜糖蛋白GPⅠb、GPⅡb、GPⅢa的分子数。结果CPB后各时间点两组血小板计数较CPB前显著减少（P〈0．01），同时间点两组间无统计学差异（P〉0．05）。CPB后两组PAR较CPB前显著下降（P〈0．01），同时间点C组PAR下降较U组更明显（P〈0．05）。CPB后两组GpⅠb、GpⅡb、GpⅢa分子数较CPB前显著减少（P〈0．01），停机后逐步恢复，同时间点C组较U组更明显（P〈0．05）。结论CPB后血小板数目减少，膜糖蛋白分子数降低，粘附能力下降。CPB前应用大剂量乌司他丁可减少CPB中血小板膜糖蛋白受体的分解，保护血小板功能。

Effect of large dose of ulinastatin on platelet during normothermia cardiopulmonary bypass in rabbits

Objective To investigate the effect of large dose of ulinastatin on platelet count and function after CPB by establishing the rabbit model of normothermia cardiopulmonary bypass. Methods Twenty rabbits are randomly assigned to control group （Group C,n=10） and experiment group （Group U, n = 10）. The rabbits in Group U are administered ulinastatin 10 × 10^4U /kg before CPB, the rabbits in Group C are received same volume of saline at the same time. All rabbits are undergoing extracorporeal circulation for 30min, at perfusion flow of 180-300ml/min, while rectal temperature being maintained from 36. 5℃ to 37.5℃. Hemodynamic parameters are recorded before CPB, at termination of CPB, 1 hour, 2 hour and 3 hour after CPB. Blood platelet count, platelet adhesion reaction and platelet membrane glycoprotein GpⅠb, GpⅡb, GpⅢa are determined at the above time point respectively. Results The platelet counts in both groups are decreased significantly after CPB （P 〈 0. 01 ）, but there are no differences between Groups after CPB （ P 〉 0. 5 ）. The platelet adhesion rates in both groups are descended after CPB （ P 〈 0. 05 ）, but the platelet adhesion ratios after CPB in Group U are significantly higher than those in Group C respectively （P 〈 0. 05）. The molecular number of GpⅠb, GpⅡb, GpⅢa in both groups are reduced after CPB （ P 〈 0. 01 ）, but the molecular numbers of GpⅠb, GpⅡb, GpⅢa after CPB in Group U are significantly higher than those in Group C respectively （P 〈0. 05 ）. Conclusion CPB results in reduced platelet count, depletes GpⅠb, GpⅡb, GpⅢa, and damages aggregation and adhesion function of the platelet. Administration of large dose of ulinastatin before CPB can inhibit breakdown of platelet membrane glycoproteins, and preserve the function of platelet.