孕早期安氟醚麻醉对大鼠子代海马NR2B表达的影响

Effect of inhalation of enflurane in early pregtmncy on the expression of NR2B in the hippocampus of off- springs of rats

目的评价孕早期安氟醚麻醉对大鼠子代海马N-甲基-D-天冬氨酸受体2B亚基（NR2B）表达的影响。方法孕8～10dSD大鼠30只，体重200～250g，采用随机数字表法，将其随机分为3组（n=10）：对照组（c组）、吸人安氟醚4h组（E1组）和吸入安氟醚8h组（E2组）。E1组和E2组分别吸入1．7％安氟醚4和8h，氧流量为2L／min，C组吸入等流量氧气。分别于出生后20和30d，采用Morris水迷宫系统测定子鼠的认知功能。于水迷宫实验结束后第2天，取各组子鼠海马组织，分别采用PCR和免疫组化法测定NR2BmRNA及蛋白的表达。结果与C组比较，E1组和E2组子鼠出生后20和30d时逃避潜伏期延长，穿越平台次数减少，平台象限停留时间缩短（P〈0．05），海马NR2BmRNA及蛋白表达下调（P〈0．05）；与E1组比较，E2组子鼠出生后20和30d时海马NR2BmR—NA及蛋白表达比较差异无统计学意义（P〉0．05）。结论孕早期安氟醚麻醉可降低大鼠子代的认知功能，其机制与抑制大鼠子代海马NR2B表达有关。

Objective To investigate the effect of inhalation of enflurane on the expression of N-methyl-D- aspartate receptor subunit 2B （NR2B）in the hippocampus of the offsprings of rats. Methods Thirty SD rats pregnancy 8-10 day weighing 200-250 g were randomly divided into 3 groups （ n = 10 each） ：control group （Group C）, 4 h inhalation of enflurane group （group E1 ） and 8 h inhalation of enflurane group （group E2 ）.Group E, and E2 inhaled 1.7 % enflurane （in 02 2 L/min） for 4 and 8 h respectively, while group C inhaled oxygen 2 L/min for 8 h. The learning and memory functions of the offsprings were assessed at 20 and 30 days after birth by Morris maze test. The expression of the NR2B mRNA were examined by RT-PCR, NR2B protein were examined by mmunohistochemistry. Results Compared with group C, the escape latency was significantly prolonged, the frequency of crossing the original platform was significantly decreased, the staying time at the original platform quadrant was significantly shortened at 3-5 days after the test in group E1 and E2 （.P 〈 0.05 ）, the expression levels of NR2B mRNA and protein were significantly decreased at 20 and 30 days after birth in group E1 and E2 （P 〈 0.05）. There were no significant differences in the indexes mentioned above between groups El and E2 （ P 〉 0.05）. Conclusion Inhalation enflurane in the early pregnancy can result in cognition dysfunction through inhibiting NR2B expression in the hippocampus of the offsprings of the rats.