七氟醚不同麻醉时间对大鼠认知功能的影响及机制.

Objective To observe the effects of different duration of sevoflurane anesthesia on the cognitive function and the expression of α7-acetylcholine receptor ( α7-nAchR ) in hippocampal neuron of rats. Methods Ninety-six SD rats were randomly divided into four groups (n = 24) ; the control group (C) which inhaled air, and three other groups which were exposed to 3% sevoflurane for 1 (Sl), 3( S2), and 5h (S3), respectively. All rats were trained 5 days by the orientation navigation experiment before anesthesia, 12 rats in each group were tested by space exploration experiment at 1 and 7 days after anesthesia, and we recorded escape latency, the duration of staying in the target quadrant, the swimming distance in target quadrant, total distance, number of crossing platforms, and calculated the ratio of the duration in the original platform quadrant to the total duration, and the ratio of the distance in the original platform quadrant to the total distance. All rats were executed at 1 and 7 days after anesthesia, the hippocampal tissues were obtained for determination of the protein and mRNA expression of α7-nAchR by Western blotting and real-time fluorescent quantitative PCR, respectively. Results Compared with the group C. the duration of staying in the target quadrant, the ratio of the duration in the o-riginal platform quadrant to the total duration, and the ratio of the distance in the original platform quadrant to the total distance were significantly decreased at 1 and 7 days after anesthesia in the S1, S2, and S3 groups ( all P <0.05 ). Compared with the S1, S2 groups, the distance of swimming in the target quadrant, the duration of staying in the target quadrant, the ratio of the duration in the original platform quadrant to the total duration, and the ratio of the distance in the original plat-form quadrant to the total distance were significantly decreased at 1 day after anesthesia in the S3 group (all P <0. 05 ). Moreover, compared with the group C. the protein and mRNA expression of α7-nAchR was significantly down-regulated at 1 and 7 d after anesthesia in the S1, S2, S3 groups ( P <0. 05 ). In the S1, S2, S3 groups, the expression of α7-nAchR protein and mRNA showed a decreasing trend, but no significant differences in the protein and mRNA expression of α7-nAchR was found (all P >0. 05 ). Conclusion Inhalation of 3% sevoflurane anesthesia for 1.3. and 5 h can lead to cognitive decline in rats, cognitive decline caused by anesthesia for 5 h is more obvious; its mechanism may be related to the down-regulation of a7-nAchR protein and mRNA expression. [ABSTRACT FROM AUTHOR]