Effect Of Different Concentrations Sevoflurone And Scopolamine On Cognition And Expression Of Macetylcholine Receptor Of Hippocampus In Aged Rats

Objective: To investigate the effect of sevoflurone and scopolamine on the expression of M(M1 and M2) acetylcholine receptor in the hippocampus and relation with the cognition of healthy aged rats.Methods: 80 SD rats weighting 550～600g were randomly divided into 5 groups(n=16):1.5%sev group; 3.0%sev group;sco group;3.0%sev+sco group and con group. Each group of rats were intraperitoneal injected scopolamine 0.8mg/kg or equal volume of normal saline,and were anesthetized 2 hours by 1.5%sevoflurone(1.5%sev group),3.0%%sevoflurone (3.0%sev group and 3.0%sev+sco group)or analogically anesthetized 2 hours by air(Con group and sco group) after 30 minutes. Y-maze was used to test the ability of learning and memory half of each group of rats after 24h and 72h. The expression of M1 acetylcholine receptor(mAChR M1) and M2 acetylcholine receptor(mAChR M2) in the hippocampus of rats were tested by RT-PCR. And we analyzed the relationship between the learning and memory's test results and the expression level of M1and M2 acetylcholine receptor.Results: The numbers and times of study in 3.0%sev group,sco group and 3.0%sev+sco group were increased compaired with that in the con group after the rats be anesthetized 24h(P<0.05). The numbers and times of study in 3.0%sev+sco group were increased compaired with that in the 3.0%sev group and sco group(P<0.05). And the mAChR M1,mAChR M2 expression levels in hippocampus of 3.0%sev group,sco group and 3.0%sev+sco group were fewer than those in the con group rats.The trend of mAChR M1,mAChR M2 expression levels changed with the abilty of learning and memory changed of every groups were consistent. There was no significant difference in the numbers and times of study among the 5 groups after be administrated 72h(.P>0.05). And hippocampal mAChR M1, mAChR M2 expression level returned to the control group.Conclusion:The ability of learning and memory of aged rats treated by sevoflurone and scopolamine were reduced in a short time. Suggesting mAChR M1 or mAChR M2 exepression levels declined may contribute to these phenomenons.