硫辛酸对帕金森病大鼠黑质线粒体的保护作用

Protection of thioctic acid in mitochondria in the rat model of Parkinson's disease

目的探讨帕金森病(PD)大鼠模型中脑线粒体的变化及硫辛酸的保护作用。方法 80只SD雄性大鼠,随机分为假手术组(20只)、模型组(60只)。将6-羟基多巴胺(6-OHDA)注入大鼠右侧纹状体建立PD模型,假手术组注入同等剂量的生理盐水。建模第4周后运用旋转实验筛选成功模型(40只),随机分为PD组(20只)、治疗组(20只),治疗组给予硫辛酸50 mg/kg·d腹腔注射,连续14 d,PD组给予同等剂量生理盐水。治疗2周后,Cylinder test分析大鼠运动能力;化学发光法检测大鼠右侧中脑黑质ATP水平;JC-1法检测中脑线粒体膜电位;免疫组化、Western blotting检测各组大鼠酪氨酸氢化酶(TH)水平;Western blotting检测HSP60的表达。结果与假手术组比较,PD组左侧肢体使用次数显著减少(P<0.05),中脑ATP水平明显降低(P<0.05),膜电位显著降低(P<0.05),TH表达水平显著降低(P<0.05),HSP60表达水平无明显变化(P>0.05);硫辛酸治疗后,治疗组左侧肢体使用次数显著上升(P<0.05),ATP水平显著升高(P<0.05),膜电位显著升高(P<0.05),TH表达水平显著增高(P<0.05),HSP60表达水平略微降低,但无统计学意义(P>0.05)。结论 PD大鼠黑质线粒体功能降低但线粒体数量无明显改变,硫辛酸可显著改善PD症状及线粒体功能。

Objective To investigate the change of mitochondria in midbrain of rat model with Parkinsons disease（PD） and the protective effect of lipoic acid on mitochondria. Methods Eighty male SD rats were randomly divided into sham group（20 rats） and model group（60 rats）. In model group,6-Hydroxydopamine（6-OHDA） was injected into the right striatum to establish the unilateral mesencephalic lesions model. The rats in sham group were injected with the same dose of saline by the same method. Four weeks after 6-OHDA lesion,40 of the successful model rats（screened by Apomorphine-induced rotation test） were selected and divided into PD group（20 rats） and treatment group（20 rats）. The rats in treatment group were intraperitoneally injected with lipoic acid（50 mg/kg） daily for 14 days. The rats in PD group were injected with the same dose saline at the same time. The motor coordination was observed by cylinder test. The ATP level and the mitochondrial membrane potential in right midbrain were detected by chemiluminescence and probe JC-1 methods respectively. The expression of TH in midbrain was detected by Western blotting and immunohistochemical staining. The expression of HSP60 in midbrain was detected by Western blotting.Results Compared with sham group,the number of touching the cylinder wall with left front leg,ATP level,the mitochondrial membrane potential and the expression of TH in PD group decreased at the same time（ P 〈 0. 05）,but the expression of HSP60 did not change significantly（ P 〉 0. 05）. Impairment of behavior,ATP level,mitochondrial membrane potential and the expression of TH recovered simultaneously after the treatment of thioctic acid（ P 〈 0. 05）,whilethe expression of HSP60 decreased too slightly（ P 〉 0. 05）. Conclusion The function of mitochondria in substantia nigra of PD rats decreases,but the number of mitochondria does not change obviously. Thioctic acid has beneficial therapeutic effect on PD by ameliorating mitochondrial function.