| Objective: A model of cognitive dysfunction in aged rats caused by inhalation of different concentrations of sevoflurane was established.By detecting the expression changes of CREB,BDNF,PKA and c AMP in the hippocampus,to explore the related mechanism of sevoflurane on the cognitive function.Methods: 105 healthy 18-20 month old SD rats were randomly divided into a control group(C group,n = 21)and an experimental group(S group,n = 84,each subgroup S1,S2,S3,S4)21 rats each),the S1-S4 subgroup inhaled 1%,2%,3%,4% sevoflurane for 6h,and the control group only inhaled 50% air-oxygen mixed gas(2L / min)for 6h.The five groups of old rats were tested for Morris water maze before and after anesthesia treatment.The tracking data(escape latency,total swimming distance,original platform crossing times and original platform quadrant residence time)were analyzed and judged whether the modeling was successful.The expression changes of CREB,BDNF,c AMP,PKA and relative expression levels of CREBm RNA and BDNFm RNA in rat hippocampus were detected by Western Blot and Real-time PCR on the 1st,3d and 7d after successful modeling.Results: 1.Morris water maze test showed that: ? on the first day after anesthesia,the escape latency,total swimming distance,crossing times of the original platform and the staying time of the original platform quadrant in S2-S4 group were statistically significant compared with those in C group(P < 0.05);? In the five groups of rats,compared with before anesthesia on the first day after anesthesia,the indicators in the S2,S3,and S4 groups were statistically significant(P < 0.05).2.The results of Western blot and real time PCR revealed that: ? the expression of CREB,BDNF,PKA,c AMP,CREBm RNA and BDNFm RNA in hippocampus of S2-S4 group were significantly decreased on the first day after inhalation of sevoflurane,compared with group C at the same time(P < 0.05);? the expression was gradually increased on the third and seventh days after anesthesia,there were difference in S2-S4 group on day 3(P < 0.05),but the seventh day was no difference among the groups(P > 0.05).Conclusion: 1.continuous inhalation of more than 2% sevoflurane for 6h can lead to cognitive dysfunction in elderly SD rats,and the effect on cognitive function increases with the increase of concentration.2.c AMP-CREB-BDNF signaling pathway may be involved in the cognitive dysfunction of the elderly SD rats induced by sevoflurane,which is related tothe down-regulation of CREB and BDNF expression after sevoflurane inhalation. |
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