ABSTRACT
Objective To evaluate the relationship between sevoflurane-induced cognitive impairment and α1B adrenoceptors (ADRA1B) and ADRA1D in the cerebral cortex of rats.Methods Forty-eight SPF adult Sprague-Dawley rats (half male,half female),weighing 220-260 g,were divided into control group (C group,n =24) and sevoflurane group (S group,n =24) using a random number table method.Group C and group S inhaled air and 3％ sevoflurane,respectively,for 5 h.Eight rats in each group were sacrificed immediately after anesthesia,and the cerebral cortex was removed.Eight rats in each group were selected on days 1 and 7 after anesthesia and underwent Barnes maze test.The rats were then sacrificed,and the cerebral cortex was removed.The expression of ADRA1B and ADRA1D protein and mRNA in cerebral cortex tissues was detected by Western blot and fluorescent quantitative real-time polymerase chain reaction,respectively.Results Compared with group C,the number of entering incorrect holes was significantly increased at 1 and 7 days after anesthesia,the latency and total distance to enter the target hole were prolonged,and the expression of ADRA1B and ADRA1D protein and mRNA in cerebral cortex was down-regulated immediately after anesthesia and at 1 and 7 days after anesthesia in group S (P＜0.05).Conclusion The mechanism underlying sevoflurane-induced cognitive impairment may be related to the down-regulated expression of ADRA1B and ADRA1D in cerebral cortex of rats.
ABSTRACT
Objective To evaluate the relationship between sevoflurane-induced cognitive decline and α1A norepinephrine receptor (ADRA1A) in the cerebral cortex of rats.Methods Forty-eight cleangrade healthy adult Sprague-Dawley rats (24 male,24 female),weighing 220-260 g,aged 3-4 months old,were divided into 2 groups (n =24 each) using a random number table method:control group (group C) and sevoflurane group (S group).Group S inhaled 3％ sevoflurane for 5 h.Rats underwent the Barnes maze test on days 1 and 7 after anesthesia.Rats were sacrificed immediately after anesthesia and on days 1 and 7 after anesthesia,and the cerebral cortex was removed for determination of the expression of ADRA1A protein and mRNA (by Western blot or fluorescent quantitative real-time polymerase chain reaction).Results Compared with group C,the number of entering incorrect holes was significantly increased,and the latency of entering the target hole and the distance were prolonged,and the expression of ADRA1A protein and mRNA in cerebral cortex was down-regulated at each time point in group S (P＜0.05).Conclusion The mechanism of sevoflurane-induced cognitive decline is related to down-regulated expression of ADRA1A in the cerebral cortex of rats.
ABSTRACT
Objective To evaluate the effect of sevoflurane anesthesia on the expression of hippocampal α4 subunit-containing nicotinic acetylcholine receptor (α4nAChR) in rats.Methods One hundred and forty-four Sprague-Dawley rats of both sexes,aged 3-4 months,weighing 220-270 g,were divided into 4 groups (n =36 each) using a random number table:control group (group C),sevoflurane anesthesia for 1 h group (group S1),sevoflurane anesthesia for 3 h group (group S2) and sevoflurane anesthesia for 5 h group (group S3).Group C inhaled air,and S1,S2 and S3 groups inhaled 3％ sevoflurane for 1,3 and 5 h,respectively.Twelve rats in each group were selected at 1 and 7 days after emergence from anesthesia to undergo spatial probe test.Rats were then sacrificed immediately after anesthesia and at 1 and 7 days after emergence from anesthesia,and hippocampi were removed for determination of the expression of α4nAchR protein and mRNA in hippocampal neurons (by Western blot or real-time polymerase chain reaction).Results Compared with group C,the duration of staying at the target quadrant was significantly shortened,and the ratio of duration of staying at the original platform quadrant to the total duration and ratio of swimming distance in the original platform quadrant to the total distance were decreased on 1 and 7 days after emergence from anesthesia,the expression of α4nAchR protein and mRNA was down-regulated,and the number of positive cells was reduced in S1,S2 and S3 groups (P＜0.05).Compared with S1 and S2 groups,the duration of staying at the target quadrant was significantly shortened,the ratio of duration of staying at the original platform quadrant to the total duration and ratio of swimming distance in the original platform quadrant to the total distance were decreased on 1 day after emergence from anesthesia in group S3 (P＜0.05).There was no significant difference in the expression of α4nAchR protein and mRNA or number of positive cells at each time point between group S1,group S2 and group S3 (P＞0.05).Conclusion The mechanism by which sevoflurane anesthesia induces cognitive dysfunction may be partially related to down-regulating the expression of hippocampal α4nAchR in rats.