小型猪复合麻醉剂及赛拉嗪对大鼠大脑皮层与小脑c-fos基因表达的影响

Effects of the combined anaesthetic for miniature pigs and Xylazine on the expression of c-fos gene in cerebral cortex and cerebellum of rats

为研究小型猪复合麻醉剂(XFM)及赛拉嗪对大鼠大脑皮层与小脑c-fos基因表达的影响,将114只SD大鼠随机分为空白对照组(B组)、生理盐水对照组(C组)、XFM麻醉组(H组)和赛拉嗪组(X组)。除B组外,各组又分为6个亚组:麻醉诱导期(Ⅰ期)、翻正反射消失(Ⅱ期)、翻正反射消失后15min(Ⅲ期)、翻正反射消失后35min(Ⅳ期)、翻正反射恢复(Ⅴ期)、恢复直线爬行(Ⅵ期)。各组大鼠在对应的时间点断头处死,分离并采集大脑皮层和小脑,并分别提取RNA和蛋白质,用实时荧光定量PCR和免疫印迹法检测各样品中c-fos基因mRNA含量和蛋白含量。结果显示:(1)C组大鼠大脑皮层与小脑c-fos基因的表达无显著变化(P>0.05);(2)H组这2个脑区c-fos基因mRNA转录量逐渐升高,在Ⅲ期达到最高(P<0.01),在麻醉苏醒过程中下调;c-fos蛋白在麻醉过程中表达量上调,在麻醉苏醒后(Ⅵ期)表达量下降(P<0.01);(3)X组上述脑区c-fos基因mRNA表达量上升,主要在Ⅱ、Ⅲ、Ⅳ、Ⅴ期明显升高(P<0.01),Ⅵ期下降至接近对照组水平;c-fos蛋白表达逐渐升高,而在Ⅴ、Ⅵ期表达下降(P<0.01),X组c-fos表达水平较H组表达水平低(P<0.01)。结果提示:在XFM和赛拉嗪麻醉过程中,大鼠大脑皮层与小脑中c-fos基因的表达量随麻醉加深而增加,在麻醉苏醒过程中表达量下降,大脑皮层及小脑可能是XFM和赛拉嗪的麻醉作用位点,两种药物对大鼠大脑皮层与小脑内c-fos基因表达的影响可能是其麻醉作用机制之一。

This study was aimed to study effects of the combined anaesthetic(XFM)and Xylazine on c-fos gene expression in cerebral cortex and cerebellum of rat.114 SD rats were randomly divided into blank control group(B group),saline solution control group(C group),XFM group(H group)and Xylazine group(X group).Each group contained six subgroups except B group:anesthesia induction stage(stageⅠ),righting reflex disappear stage(stageⅡ),15 min after righting reflex disappear(stageⅢ),35 min after righting reflex disappear(stageⅣ),righting reflex recovery stage(stageⅤ)and recovery of linear crawling(stageⅥ).Rats were decapitated at the corresponding time,then the cerebral cortex and the cerebellum were separated.RNA and protein were extracted from these brain tissue,and used for the detection of c-fos mRNA and protein content by the real-time qPCR and Western-blot methods.From the results,in C group,the expression of c-fos gene had no significant changes(P>0.05),and in H group,c-fos mRNA transcription levels gradually increased in these encephalic regions.Transcript level of them was highest in stage Ⅲ(P<0.01),but decreased when recovered from anesthesia.The expression of c-fos protein was increased in these encephalic regions,and decreased in stageⅥ(P<0.01);(3)In X group,c-fos mRNA transcription levels increased in the two encephalic regions,mainly increased in stagesⅡ,Ⅲ,ⅣandⅤ(P<0.01),while in stageⅥ was decreased as the level of control group;c-fos protein expression gradually increased in these encephalic regions,and decreased in stagesⅤandⅥ(P<0.01),c-fos protein expression level in X group is lower than XFM group(P<0.01).During rats anesthetized with XFM and Xylazine,the expression level of c-fos increased in cerebral cortex and cerebellum followed with the deepening of anaesthesia,and decreased when recovery from anesthesia.This indicated that the two encephalic regions may be the central action sites of XFM and Xylazine.The expression of c-fos protein induced by XFM and Xylazine in cerebral cortex and cerebellum may be one of the anesthesia mechanisms.