MTBE对大鼠中枢神经系统Fos蛋白的影响

目的通过研究甲基叔丁基醚(MTBE)对大鼠中枢神经系统Fos蛋白的影响,探讨MTBE对中枢神经系统急性毒作用部位。方法54只健康成年SD大鼠,体重180～220g,随机分为9组,腹腔注射MTBE原液染毒,以未染毒为对照,染毒剂量分别为700、1050、1400mg/(kg·bw),染毒后用免疫组织化学方法检测Fos蛋白的表达并用相对灰度值定量。结果未染毒对照组脑组织神经元内仅有少量Fos蛋白表达,MTBE急性染毒后在大脑皮质、丘脑、下丘脑、小脑皮质神经元内Fos蛋白表达均有明显增多,Fos蛋白表达的相对灰度值随着MTBE染毒剂量的增加,其表达逐渐增强,其中MTBE对大脑皮质、小脑皮质的毒作用较丘脑、下丘脑更为明显;各部位Fos蛋白在MTBE染毒后0.5h时表达开始增加,1.0h达到高峰,2.0h时开始减弱,8.0h时Fos蛋白表达恢复到染毒前水平。结论MTBE可诱导大脑皮质、小脑皮质、丘脑和下丘脑Fos蛋白的表达增强,大脑皮质、小脑皮质、丘脑和下丘脑是MTBE的急性毒作用部位。

The Fos protein levies in central nervous system in rats exposed to methyl tertiary butyl ether

Objective To investigate the effects of methyl tertiary butyl ether(MTBE)on the FOS protein in central nervous system of the rats.Methods 54 SD healthy adult-rats weighed 180～220g were involved in this study.They were randomly divided into 9 groups and were given intr-abdominal MTBE injection.The MTBE ex- posure dosages were 700,1050,and 1400mg/(kg·bw).After the rats were exposed to MTBE,an immunohistoche- mical method was used to detect the FOS protein levels and the Gray-value was determined.The control group was given normal saline.Results Less Fos protein expression was found in the control group.After exposed to MTBE,an acutely elevated Fos protein level in cerebral cortex,thalamus and cerebellar cortex neurons were found. An relative Gray-value was intensified as the increasing of Fos protein.The toxic target sites in cerebral cortex and cerebellar cortex were more clear than those thalamus and hypothalamus.The Fos expression in each sites were ele- vated 0.5 hour after MTBE exposure,the peak expression was found at 1.0 hour,a diminishing level was found at 2.0 hour,and the Fos protein level returned to the levels' before MTBE exposure at 8 h.Conclusion The elevated Fos protein in cerebral cortex,cerebellar cortex and hypothalamus can be induced by MTBE,the acute toxic target sites of MTBE are cerebral cortex,cerebellar cortex and hypothalamus.