α硫辛酸对后肢缺血再灌注损伤大鼠血神经屏障的保护作用研究

Study on the protective effects of alpha lipoic acid on blood nerve barrier with posterior limb ischemia reperfusion injury in rats

目的:研究α硫辛酸(ALA)对大鼠后肢缺血再灌注(I/R)损伤后血神经屏障的保护作用。方法:54只成年雄性SD大鼠分为3组,分别为假手术组(sham)、缺血再灌注模型组(I/R)和ALA处理组(ALA),通过手术结扎大鼠左侧髂总动脉4 h制备后肢I/R注模型,ALA处理组大鼠于术前7 d连续给予ALA。伊文思蓝(EB)渗透实验检测血神经屏障的通透性,分别于再灌注后24 h检测各组大鼠坐骨神经组织中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性,以及丙二醛(MDA)的含量,应用Western Blot检测坐骨神经组织中紧密连接蛋白occludin和claudin-5表达变化。结果:与sham组相比,I/R组大鼠坐骨神经EB漏出增多(P <0. 05),SOD和GSH-Px活性降低(P <0. 05),MDA水平升高(P <0. 05),occludin和claudin-5蛋白表达下降(P <0. 05);ALA预处理的大鼠EB漏出减少(P <0. 05),GSH-Px和SOD活性增加(P <0. 05),MDA水平降低(P <0. 05),occludin和claudin-5蛋白表达增加(P <0. 05)。结论:ALA通过抑制机体的氧化应激水平对I/R损伤大鼠的血神经屏障起到保护作用。

Objective:To investigate the effects of alpha lipoic acid(ALA)on blood nerve barrier with posterior limb induced by ischemia-reperfusion(I/R)injury in rats.Methods:Total 54 male SD rats were assigned to 3 groups:including sham group,I/R group and ALA treatment group.Hind limbs I/R model were prepared by surgical ligation of left common iliac artery of rats.Rats were given ALA for 7 consecutive days before operation in ALA group.Blood nerve barrier permeability was tested by Evans blue(EB)infiltration test.The activity of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and malondialdehyde(MDA)levels in the sciatic nerve tissues of rats were measured by kits 24 h after reperfusion,respectively.The expression of occludin and claudin-5 proteins in sciatic nerve tissues were tested by Western Blot.Results:The I/R group rats showed EB leakage significantly higher than those in the sham group(P<0.05).The GSH-Px and SOD activities decreased(P<0.05),MDA levels increased(P<0.05),and the protein expression of occludin and claudin-5 was down regulated(P<0.05).After pretreatment with ALA,EB leakage decreased(P<0.05),the GSH-Px and SOD activities increased(P<0.05),MDA levels decreased(P<0.05),and the protein expression of occludin and claudin-5 was up regulated(P<0.05).Conclusion:ALA can protect the blood nerve barrier through suppression oxidative stress in I/R injury rats.