单侧前庭功能丧失大鼠患侧前庭内侧核及小脑绒球中GLU-IR、GFAP、GABA B2的表达

Study on the Expression of Glu-IR,GFAP and GABA B2 in the Medial Vestibular Nucleus and Cerebellar Chorionic Villi in Rats with Unilateral Vestibular Dysfunction

目的探讨单侧前庭功能丧失大鼠中枢代偿的机制。方法将45只成年健康SD大鼠随机分为空白对照组(n=9)、生理盐水注射组(n=18)、模型组(n=18)。每组大鼠随机确定实验耳侧别,空白对照组正常饲养,生理盐水注射组鼓室内一次性注射生理盐水0.1~0.2毫升/耳,模型组鼓室内一次性注射50%氯仿0.1~0.2毫升/耳,制造单侧前庭功能丧失大鼠模型,注射后1 h进行模型评价。造模成功3天后,采用免疫组化法、PCR法及Western-blot法观察实验耳侧前庭内侧核、小脑绒球中谷氨酸免疫反应物(GLU-IR)、星形胶质细胞(GFAP)、γ氨基丁酸B2受体(GABA B2)的表达。结果造模成功3天后,生理盐水注射组前庭内侧核、小脑绒球中GLU-IR、GFAP、GABA B2的表达与空白对照组比较,差异无统计学意义(P>0.05);模型组与生理盐水注射组、空白对照组比较GLU-IR表达明显下调(P<0.05),GFAP、GABA B2的表达明显上调(P<0.05);模型组前庭内侧核GLU-IR、GFAP、GABA B2表达量与小脑绒球比较差异无统计学意义(P>0.05)。结论单侧前庭功能丧失可导致患侧前庭内侧核、小脑绒球中GLU-IR表达下调,GFAP、GABA B2表达上调,这或为前庭代偿的可能机制。

Objective To investigate the mechanism of central compensation in rats with unilateral vestibular dysfunction.Methods A total of 45 adult healthy SD rats were randomly divided into blank control group(n=9),sham operation control group(n=18)and model group(n=18).Each group of rats was randomly assigned to experiment ear.The rats in the control group were fed with normal diet,the rats in the sham-operated control group were injected with 0.1~0.2 ml/ear of normal saline,and the rats in the model group were injected with 0.1~0.2 ml/ear of chloroform(50%),the model was evaluated 1 h after injection.The expressions of GLU-IR,GFAP and GABA B2 in the medial vestibular nucleus and cerebellar villi were observed by immunohistochemistry,PCR and Western-blot after 3 days.Results Three days later,there was no significant difference in Glu-IR,GFAP and GABA B2 between the sham operated control group and the blank control group(P>0.05).The expression of Glu-IR in model group was significantly lower than that in sham operation group and blank control group(P<0.05).The expression of GFAP and GABA B2 was up-regulated(P<0.05).There was no significant difference in Glu-IR,GFAP,GABA B2 between the medial vestibular nucleus and cerebellar choriocytes in the model group(P>0.05).Conclusion The loss of unilateral vestibular function may result in the down-regulation of Glu-IR expression and the up-regulation of GFAP and GABA B2 expression in the medial vestibular nucleus and cerebellar choriocyte of the affected side,which may be the possible mechanism of vestibular compensation.