乌司他丁对肝部分切除术后小鼠远期学习记忆能力的影响

Effects of ulinastatin on long-term learning and memory function after partial hepatectomy in mice

目的 观察乌司他丁（UTI）对肝部分切除术（PH）后小鼠远期学习记忆能力的影响.方法 无特定病原体（SPF）级成年雄性C57BL/6J小鼠45只,采用随机数字表法分为3组：对照组（C组）、PH组和UTI组,每组15只.UTI组小鼠术毕苏醒即刻经腹腔注射UTI 50 000 U/（kg＆#183;d）,C组和PH组小鼠每日腹腔注射等量生理盐水,连续30 d.3组小鼠于末次给药后24h进行Morris水迷宫试验.学习记忆能力测试完毕后处死小鼠,留取海马组织,检测海马组织湿/干重比（W/D）和总含水量（TWC）,反转录-聚合酶链反应（RT-PCR）和Westem blot分别检测海马组织CCAAT增强子结合蛋白同源蛋白（CHOP） mRNA及蛋白表达,原位末端细胞凋亡检测（TUNEL）法检测海马组织细胞凋亡指数（AI）.结果 与C组[（17.39 ±7.72）、（12.59 ±6.69）s;（2 122.57± 543.48）、（1 123.69±369.32） mm]比较,PH组小鼠第3、4天的逃避潜伏期[（54.48±9.69）、（56.63 ±7.74）s]及游泳距离[（4 789.48±677.67）、（4987.72 ±884.53） mm]均延长（P＜0.05）,海马组织W/D（5.47 ±0.98比2.79 ±0.78）、TWC（4.43±0.97比1.79±0.72）及AI[（36.32 ±2.62）％比（2.69±0.75）％]均增加（P＜0.05）,海马组织CHOP mRNA（0.92 ±0.36比0.38 ±0.08）及蛋白表达（2.79 ±0.79比1.06±0.23）均增加（P＜0.05）.与PH组比较,UTI组小鼠第3、4天的逃避潜伏期[（23.56 ±7.47）s、（13.62±6.36）s]及游泳距离[（2 234.64 ±890.58） mm、（1 120.67 ±389.74） mm]均缩短（P＜0.05）,海马组织W/D（2.92 ±0.64比5.47 ±0.98）、TWC（1.86±0.84比4.43 ±0.97）及AI[（13.65±1.74）％比（36.32±2.62）％]均减少（P＜0.05）,海马组织CHOP mRNA（0.54 ±0.11比0.92±0.36）及蛋白表达（1.41±0.47比2.79±0.79）均降低（P＜0.05）.结论 UTI可提高PH后小鼠远期学习记忆能力,其机制可能其与抑制海马组织中CHOP介导的细胞凋亡有关.

Objective To investigate the effect of ulinastatin （UTI） on long-term learning and memory function after partial hepatectomy （PH） in mice.Methods Forty-five adult male specific pathogen free （SPF） C57BL/6J mice were randomly divided into control group （C group）,PH group and UTI group （n =15 each）.After the mice regained consciousness after operation,animals received intraperitoneally UTI at a dose of 50 000 U/（kg＆#183;day） for 30 consecutive days in UTI group.Animals were given intraperitoneally with the same volume of normal saline for 30 consecutive days in C group and PH group.The mice of the three groups underwent Morris water maze test at 24 h after the last pretreatment.The mice were euthanized after the test of learning and memory function,and hippocampi tissue was immediately excised for determination of wet weight to dry weight （W/D） and total water content （TWC）.The expression levels of CCAAT enhancer-binding proteins homologous protein （CHOP） mRNA and protein of hippocampi tissue were detected respectively by reverse transcription-polymerase chain reaction （RT-PCR） and Western blotting.Apoptosis index （AI） of hippocampi tissue was determined by terminal-deoxynucleoitidyl transferase mediated nick end labeling （TUNEL） assay.Results Compared to C group [（17.39 ± 7.72） s,（12.59 ±6.69） s;（2 122.57 ±543.48） mm,（1 123.69 ±369.32） mm],the escape latency [（54.48 ± 9.69） s,（56.63 ± 7.74） s] and swimming distance [（4789.48± 677.67） mm,（4 987.72 ± 884.53） mm] were significantly prolonged （both P 〈 0.05）,W/D （5.47 ± 0.98 vs.2.79 ± 0.78）,TWC （4.43 ±0.97 vs.1.79±0.72） andAI [（36.32±2.62）% vs.（2.69±0.75）%] were significantly increased （all P 〈 0.05）,and the expression levels of CHOP mRNA （0.92 ± 0.36 vs.0.38 ± 0.08） and protein （2.79 ± 0.79 vs.1.06 ± 0.23） of hippocampi tissue were significantly increased （both P 〈0.05） in PH group.Compared to PH group,the escape latency [（23.56 ±7.47） s,（13.62 ±6.36） s] and swimming distance [（2 234.64 ±890.58） mm,（1 120.67 ±389.74） mm] were significantly shortened （bothP〈0.05）,W/D （2.92 ±0.64 vs.5.47 ±0.98）,TWC （1.86 ±0.84 vs.4.43 ±0.97） and AI [（13.65 ± 1.74） % vs.（36.32 ± 2.62） %] were significantly reduced （all P 〈 0.05）,and the expression levels of CHOP mRNA （0.54 ±0.11 vs.0.92 ±0.36） and protein （1.41 ±0.47 vs.2.79 ±0.79） of hippocampi tissue were significantly reduced （both P 〈 0.05） in UTI group.Conclusion The pretreatment of UTI could improve the long-term learning and memory function after PH in mice,which might be contributed to the inhibition of apoptosis mediated by CHOP in hippocampi tissue.