异氟醚对老龄大鼠海马UCH-L1 mRNA表达的影响

Effect of isoflurane on expression of hippocampai ubiquitin C-terminal hydrolase-L1 mRNA in aged rats

目的 评价异氟醚对老龄大鼠海马泛素C末端水解酶（UCH-L1）mRNA表达的影响.方法 清洁级健康雄性SD大鼠36只,体重500～700 g,20月龄,采用随机数字表法分为2组：对照组（C组,n=12）和异氟醚组（I组,n=24）,I组持续吸入2%异氟醚2 h.I组分别于异氟醚停止吸入24 h（T1）和72 h（T2）时随机取12只大鼠行Y型迷宫实验,Y型迷宫实验结束后立即处死大鼠取海马组织,采用免疫组化法检测UCH-L1表达,实时荧光定量PCR（RT-PCR）法检测UCH-L1 mRNA表达.结果 与C组比较,I组T1时达标训练总次数增多,海马组织UCH-L1 mRNA表达下调（P〈0.05）,T2时差异无统计学意义（P〉0.05）.结论 异氟醚致老龄大鼠认知功能下降的机制可能与其下调海马组织UCH-L1 mRNA的表达有关.

Objective To evaluate the effect of isoflurane on the expression of hippocampal ubiq-uitin C-terminal hydrolase-L1（UCH-L1）mRNA in aged rats. Methods Thirty-six pathogen-free healthy male Sprague-Dawley rats, aged 20 months, weighing 500-700 g, were divided into 2 groups using a ran-dom number table： control group（group C, n=12）and isoflurane group（group I, n=24）. In group I, 2% isoflurane was continuously inhaled for 2 h. Twelve rats were selected at 24 and 72 h after stopping isoflurane inhalation（T1,2）, and Y-maze test was performed to evaluate cognitive function. The animals were sacrificed after the end of Y-maze test and their hippocampi were removed for determination of UCH-L1 expression（by immuno-histochemistry）and UCH-L1 mRNA expression（by real-time polymerase chain reaction）. Results Compared with group C, the total number of training achieving the standard was sig-nificantly increased at T1（P〈0.01 or 0.05）, and the expression of UCH-L1 mRNA was down-regulated, and no significant change was found at T2in group I（P〉0.05）. Conclusion The mechanism by which isoflurane induces cognitive decline may be related to down-regulating the expression of UCH-L1 mRNA in hippocampal tissues of aged rats.