ABSTRACT
Objective To evaluate the changes in the expression of hippocampal α7 nicotinic ace-tylcholine receptor (α7nAChR) , acetylcholinesterase ( AChE) and choline acetyltransferase ( ChAT) after sevoflurane anesthesia in neonatal rats. Methods Seventy-two healthy Sprague-Dawley rats of both sexes, aged 7 days, weighing 25-40 g, were divided into 3 groups ( n=24 each) using a random number table method: control group ( group C) , air and oxygen group ( group A∕O) and sevoflurane group ( group S) . Rats were exposed to carrier gas ( air 1 L∕min plus oxygen 1 L∕min) for 2 h in group A∕O. Rats were ex-posed to 3. 4％ sevoflurane in carrier gas for 2 h in group S. Eight rats in each group were selected at 2 h, 1 week and 4 weeks after the end of inhalation, and sacrificed, brains were removed and hippocampal tis-sues were obtained for determination of α7nAChR, AChE and ChAT protein and mRNA by Western blot and real-time polymerase chain reaction, respectively. Results Compared with group A∕O, the expression of α7nAChR mRNA was significantly down-regulated at each time point after the end of inhalation, and the expression of TnAChR was down-regulated at 2 h after the end of inhalation and up-regulated at 1 week after the end of inhalation, the expression of AChE mRNA was up-regulated at 2 h after the end of inhalation and down-regulated at 4 weeks after the end of inhalation, the expression of AChE was down-regulated at 4 weeks after the end of inhalation, the expression of ChAT mRNA was up-regulated at 2 h after the end of in-halation, and the expression of ChAT was down-regulated at each time point after the end of inhalation in group S ( P<0. 05) . Conclusion The expression of hippocampal α7nAChR is down-regulated at first and then up-regulated after sevoflurane anesthesia, the expression of ChAT and AchE in the later period is down-regulated, the tendency of protein expression mentioned above is different from that of its mRNA ex-pression, suggesting that sevoflurane may affect the protein expression through other pathways.
ABSTRACT
Objective To investigate the expression of alpha 7 nicotinic acetylcholine receptor (α7 nAchR), cholinesterase (AChE), choline acetyl translocase (ChaT) after sevoflurane anesthesia. Methods A total of 120 healthy Sprague-Dawley rats with both two genders, aged 1 week, were randomly divided into 5 groups: blank group; air/O2 group; sevoflurane group (group SEV); α7 nAchR agonist group (group PUN); α7 nAchR antagonist group (group MLA), 24 in each group. Blank group received free feeding, air/O2 group was inhaled 60％ oxygen (carrier gas: 1 L/min O2+1 L/min air) 2 h; group SEV was inhaled 3.4％ sevoflurane and carrier gas for 2 h; group PUN and group MLA were injected with PNU-282987 and methyllycaconitine, respectively, after 24 h inhaled of 3.4％ sevoflurane and carrier gas for 2 h. After that, hippocampus dissection carried out in 2 h, 1 w, 4 w, and Western blot method was used to detect α7 nAchR, AChE, ChaT proteins expression. Results Two hours after anesthesia recovery, α7 nAchR in groups SEV, PNU and MLA was significantly lower than that in air/O2 group (P ＜ 0.05); AChE in groups PNU and MLA was significantly lower than that in air/O2 group (P ＜ 0.05); ChaT in groups SEV, PNU and MLA was significantly lower than that in air/O2 group (P ＜ 0.05). One week after anesthesia recovery, α7 nAchR in blank group and groups SEV and PNU was significantly higher than that in air/O2 group (P ＜ 0.05), α7 nAchR in group MLA was significantly lower than that in air/O2 group (P ＜ 0.05); AChE in blank group and and group PNU was significantly higher than that in air/O2 group (P ＜ 0.05), ChaT in blank group was significantly higher than that in air/O2 group (P ＜ 0.05), ChaT in group SEV was significantly lower than that in air/O2 group (P ＜ 0.05). Four weeks after anesthesia awake, AChE in each group was not statistically significant; α7 nAchR in group SEV was significantly higher than that in blank group (P ＜ 0.05), α7 nAchR in group PNU and MLA was significantly lower than that in blank group (P ＜ 0.05); ChaT in blank group and group PNU was significantly lower than that in air/O2 group (P ＜ 0.05), ChaT in group MLA was significantly higher than that in air/O2 group (P ＜ 0.05). Conclusion Sevoflurane inhalation can inhibit ChaT, α7 nAChR, which had no direct effect on AChE; α7 nAChR agonist can effectively help α7 nAChR and ChaT inhibition inhaled sevoflurane, and reached a peak at about 1 week; oxygen concentration around 60％ can increase α7 nAChR expression quantity, to a certain extent against sevoflurane inhibition.