异氟醚麻醉对成年大鼠海马、皮质NR1表达及神经细胞凋亡的影响

Effects of isoflurane anesthesia on NR1 expression and neuronal apoptosis in hippocampus and cortex of adult rats

目的：评价异氟醚麻醉对成年大鼠海马、皮质含1亚基的N-甲基-D-天冬氨酸受体（NR1）表达及神经细胞凋亡的影响。方法清洁级健康成年雄性SD大鼠36只，体重250～280 g ，采用随机数字表法分为对照组（C组，n＝6）、吸入氧气组（O组，n＝6）和异氟醚麻醉组（I组，n＝24）。I组吸入2％异氟醚2 h ，O组吸入纯氧，C组吸入空气。于大鼠苏醒后2 h、1、7和14 d （T1-4）时行Morris水迷宫实验，随后处死大鼠取脑，分离海马及皮质，采用SABC法分别检测NR1表达，TUNEL法测定神经细胞凋亡指数。结果与C组比较，I组T2时逃避潜伏期和T1，2时总路程延长，T1，2时海马NR1表达下调，O组和I组皮质NR1表达下调（ P＜0.05）。3组神经细胞凋亡指数比较差异无统计学意义（ P＞0.05）。结论异氟醚麻醉可一过性降低成年大鼠的认知功能，与抑制海马NR1表达上调有关，与神经细胞凋亡无关。

Objective To evaluate the effects of isoflurane anesthesia on NR1 expression and neuronal apoptosis in the hippocampus and cortex of adult rats .Methods Thirty-six adult male Sprague-Dawley rats , weighing 250-280 g ,were randomly assigned into 3 groups using a random number table ：control group （group C , n=6 ） ,O2 inhalation group （group O , n=6 ） and isoflurane anesthesia group （group I , n=24 ） .The rats were exposed to 2% isoflurane （group I） ,to pure oxygen （group O） ,or to air （group C） for 2 h .At 2 h ,and 1 ,7 and 14 days after the rats were awake （T1-4 ） ,Morris water maze test was performed .The rats were then sacrificed and brains were removed for isolation of the hippocampus and cortex .NR1 expression was detected using SABC immuno-histochemical technique and neuronal apoptosis was determined using TUNEL .Results Compared with group C , the escape latency at T2 and total swimming distance at T1 ,2 were significantly prolonged , and the expression of NR1 in hippocampi was down-regulated at T1 ,2 in group I ,and the expression of NR1 in the cortex was down-regulated in O and I groups （ P 0.05 ） .Conclusion Isoflurane anesthesia can decrease the cognitive function transiently ,which is related to inhibition of up-regulation of NR1 expression in the hippocampi ,but not related to neuronal apoptosis in adult rats .