七氟醚对幼鼠海马发育的神经毒性作用及其机制研究

Neurotoxic effects and mechanism of sevoflurane on hippocampal development in juvenile rats

目的研究七氟醚对幼鼠海马发育的神经毒性作用及其机制。方法按照体重将幼鼠随机分为4组:第1干预组、第2干预组、第3干预组及第4干预组,每组25只。第1干预组暴露于30%O2中;第2干预组暴露于3%七氟醚+30%O2中,前5 min诱导流速为6 L·min^-1,然后以1 L·min^-1维持,持续4 h;第3干预组给予0.9%NaCl,随后处理与第1干预组相同;第4干预组幼鼠腹腔注射40 mg·kg^-1的LY294002,七氟醚暴露过程与第2干预组一致。用蛋白质印迹法检测海马磷脂酰肌醇3激酶(PI3K)、蛋白激酶B(Akt)和缝隙连接蛋白43(Cx43)的蛋白表达量。结果第1干预组、第2干预组、第3干预组和第4干预组幼鼠第7天海马脑组织中Cx43蛋白相对表达量分别为0.69±0.09,0.72±0.10,0.44±0.05和0.61±0.05;这4组的PI3K蛋白相对表达量分别为0.88±0.07,1.13±0.11,0.62±0.04和0.71±0.06;这4组的Akt蛋白相对表达量分别为1.38±1.03,1.51±1.01,0.70±0.06和0.74±0.06。上述指标:第2干预组与第1干预组比较,差异均有统计学意义(均P<0.05);第4干预组与第2干预组比较,差异均有统计学意义(均P<0.05)。结论七氟醚可能通过激活PI3K/Akt信号通路增加Cx43蛋白表达,并诱导海马神经元凋亡,增加幼鼠认知功能损伤。

Objective To investigate the neurotoxic effect and mechanism of sevoflurane on hippocampal development in juvenile rats.Methods Juvenile rats were randomly divided into 4 groups:Intervention-1 group,intervention-2 group,intervention-3 group and interention-4 group,with 25 rats in each group.The intervention-1 group was exposed to 30% O2.The intervention-2 group was exposed to 3% sevoflurane+30% O2,and the induced flow rate was 6 L·min^-1 for the first 5 min,and then maintained at 1 L·min^-1 for 4 h.The intervention-3 group was given 0.9% NaCl,the subsequent treatment is the same as the first intervention group.Juvenile rats in the intervention-4 group were intraperitoneally injected with LY294002 at 40 mg·kg^-1,the exposure process of sevoflurane was the same as that in the intervention-2 group.Western-blot was used to detect the protein expression of hippocampus phosphatidylinositol 3 kinase(PI3K),protein kinase B(serine-threonine kinase,Akt)and connexin 43(Connexins 43,Cx43)in hippocampal brain tissue of juvenile rats.Results The relative expression levels of Cx43 protein in intervention-1,-2,-3 and-4 groups on the 7th day were 0.69±0.09,0.72±0.10,0.44±0.05 and 0.61±0.05;the relative expression of PI3K protein in the 4 groups were 0.88±0.07,1.13±0.11,0.62±0.04 and 0.71±0.06;the relative expression levels of Akt protein in the 4 groups were 1.38±1.03,1.51±1.01,0.70±0.06 and 0.74±0.06.The above indicators:The differences between intervention-2 group and intervention-1 group were statistically significant(all P<0.05);the differences between intervention-4 group and intervention-2 group were statistically significant(all P<0.05).Conclusion Sevoflurane may increase the expression of Cx43 protein by activating PI3K/Akt signaling pathway,inducing apoptosis of hippocampal neurons,and increasing cognitive impairment in juvenile rats.