摘要目的 探讨乌司他丁对治疗性低温用于心搏骤停大鼠脑复苏的改良作用.方法 清洁级健康雄性SD大鼠60只,体重280～ 320 g,采用随机数字表法分为5组(n=12):假手术组(Sham组)、心搏骤停/心肺复苏组(CA/CPR组)、治疗性低温组(TH组)、乌司他丁组(U组)和乌司他丁+治疗性低温组(U+TH组).采用经食道电刺激诱发心搏骤停,4 min时行心肺复苏术的方法制备大鼠心搏骤停/心肺复苏模型.TH组于自主循环恢复即刻用乙醇涂擦大鼠体表,15 min内将直肠温度降至32～34℃,维持6h;U组于自主循环恢复即刻经股静脉注射乌司他丁100 000 U/kg;U+TH组于自主循环恢复即刻静脉注射乌司他丁100 000 U/kg并进行降温处理.于自主循环恢复后24和72 h时进行神经功能评分;于自主循环恢复后72 h完成神经功能评分后,处死大鼠,取海马组织,光镜下观察海马CA1区病理学结果;采用免疫组织化学染色法和Western blot法检测海马caspase-3的表达,Western blot法检测海马Bax和Bcl-2的表达,计算Bax/Bcl-2比值.结果 与Sham组比较,CA/CPR组自主循环恢复后神经功能评分降低,海马caspase-3和Bax表达上调,Bcl-2表达下调,Bax/Bcl-2比值升高(P＜0.05);与CA/CPR组比较,TH组和U+TH组自主循环恢复后24和72 h时、U组自主循环恢复后24 h神经功能评分升高,TH组、U组和U+TH组自主循环恢复后72 h时海马caspase-3表达下调,Bcl-2表达上调,Bax/Bcl-2比值降低,U组和U+TH组海马Bax表达下调(P＜0.05);与TH组或U组比较,U+TH组自主循环恢复后24 h时神经功能评分升高,自主循环恢复后72 h时海马caspase-3表达下调,Bax/Bcl-2比值降低(P＜0.05).U+TH组海马组织病理学损伤较TH组或U组减轻.结论 乌司他丁可改良治疗性低温对心搏骤停大鼠的脑复苏效果,机制可能与抑制神经元凋亡有关.

abstractsObjective To investigate the efficacy of ulinastatin for improvement of cerebral resuscitation using therapeutic hypothermia (TH) in rats with cardiac arrest (CA).Methods Sixty pathogenfree healthy male Sprague-Dawley rats,weighing 280-320 g,were divided into 5 groups (n =12 each) using a random number table:sham operation group (group Sham);CA/cardiopulmonary resuscitation (CPR) group (group CA/CPR);group TH;ulinastatin group (group U);ulinastatin + TH group (group U+TH).CA was induced through transesophageal cardiac pacing,and CPR was performed at 4 min of untreated arrest to establish CA/CPR model.In group TH,the rectal temperature was cooled down to 32-34 ℃ by rubbing the body surface with ethanol within 15 min starting from the time point immediately after restoration of spontaneous circulation (ROSC),and maintained at this level for 6 h.In group U,ulinastatin 100 000 U/kg was injected via the femoral vein immediately after ROSC.In group U+TH,ulinastatin 100 000 U/kg was intravenously injected immediately after ROSC,and rectal cooling was then started.The neurological function was evaluated and scored at 24 and 72 h after ROSC.The rats were sacrificed after the neurological function was scored at 72 h after ROSC,and the hippocampi were removed for microscopic examination of pathological changes in hippocampal CA1 region and for determination of caspase-3 expression (by immunohistochemical staining and Western blot) and Bax and Bcl-2 expression (by Western blot) in hippocampal tissues.Bax/Bcl-2 ratio was calculated.Results Compared with group Sham,the neurological function score was significantly decreased,the expression of caspase-3 and Bax was up-regulated,the expression of Bcl-2 was down-regulated,and Bax/Bcl-2 ratio was increased after ROSC in group CA/CPR (P＜0.05).Compared with group CA/CPR,the neurological function score was significantly increased at 24 and 72 h after ROSC in TH and U+TH groups and at 24 h after ROSC in group U,caspase3 expression was significantly down-regulated,Bcl-2 expression was up-regulated,and Bax/Bcl-2 ratio was decreased at 72 h after ROSC in TH,U and U+TH groups,and the expression of Bax was significantly down-regulated in U and U+TH groups (P＜0.05).Compared with group TH or group U,the neurological function score was significantly increased at 24 h after ROSC,and the expression of caspase-3 was downregulated and Bax/Bcl-2 ratio was decreased at 72 h after ROSC in group U+TH (P＜0.05).The pathological changes of hippocampal tissues were significantly mitigated in group U+TH when compared with group TH or group U.Conclusion Ulinastatin can improve the efficacy of TH for cerebral resuscitation in rats with cardiac arrest,and the mechanism may be related to inhibition of neuronal apoptosis.