Effect of sevoflurane on cognitive function and expression of GABA receptor 1 and NMDA receptor 2B in frontal cortex in aged rats / 临床麻醉学杂志

ABSTRACT

Objective To observe the change of learning and memory and the expression change of GABAR1 and N-methyl-D-aspartate receptor 2B (NMDAR2B)in right frontal lobe of the brain of the aged rats after the inhalation of sevoflurane.Methods Fifty male SD rats were randomly divided into control group (group C,n=10)and experimental group (group T,n=40).The control group received air at room tempreture.Experimental groups were divided into two groupsgroup T1 (2 h)and group T2 (4 h)according to the time of inhalation of sevoflurane at 3% concentration.Ev-ery group was equally divided into two groups and Morris water maze was performed on day 1 and day 7 after sevoflurane inhalation.Then the right frontal lobe was gathered and the mRNA transcription and protein expression of GABAR1 and NMDAR2B were detected by Quantitative Real-time PCR and immunofluorescence technique.Results Compared with group C,the escape latency was prolonged in groups T1 and T2 after 1 day of inhalation of sevoflurane (P<0.05),and the times of space explora-tion reduced (P<0.05).mRNA transcriptional and protein content of GABAR1 were significantly upregulated in frontal lobes of groups T1 and T2,mRNA transcriptional and protein content of NMDAR2B were significantly down-regulated (P<0.05).After inhalation of sevoflurane for 7 days, the protein expression of NMDAR2B in the frontal lobe of group T1 was lower than that of group C (P<0.05).In group T2,the escape latency was prolonged (P<0.05),the number of space explo-ration traversals was decreased (P<0.05),the expression of GABAR1 protein in frontal lobe was up-regulated (P<0.05),and the expression of NMDAR2B protein was down-regulated (P<0.05), and the amplitude was higher than that in group T1 (P<0.05).Conclusion Continuous inhalation of sevoflurane can reduce the spatial memory ability of aged rats,and the effect of prolonged inhalation is greater and longer.This effect is related to the expression of neurotransmitter receptors such as GABAR1 and NMDAR2B in the frontal lobe.