熊去氧胆酸对大鼠脑缺血再灌注损伤的保护作用及机制研究

Protective effect and mechanism of ursodeoxycholic acid on cerebral ischemia-reperfusion injury in rats

目的探究熊去氧胆酸(UDCA)对大鼠脑缺血再灌注损伤的保护作用及其机制。方法雄性SD大鼠40只按照随机数字表法分为假手术组、大脑中动脉阻塞(MCAO)组、UDCA 60 mg/kg组及UDCA 120 mg/kg组,每组10只。大鼠预防性给药3 d,用线栓法构建MCAO模型,阻塞1.5 h后实现再灌注,大鼠继续给药5 d,于末次给药0.5 h后,采用Longa’s的评分标准对大鼠神经功能进行评分。2,3,5-三苯基氯化四氮唑染色计算大鼠脑梗死体积,检测大鼠脑缺血组织中超氧化物歧化酶(SOD)、丙二醛(MDA)含量及大鼠海马组织中PI3K、p-AKT蛋白表达。结果MCAO组大鼠神经功能评分高于假手术组(P<0.01)。UDCA 60 mg/kg组、UDCA 120 mg/kg组大鼠神经功能评分均低于MCAO组(P<0.05)。假手术组脑组织全部为玫瑰红色,未见梗死病灶;MCAO组大鼠脑梗死区显示明显的苍白色梗死区。MCAO组大鼠脑梗死组织百分比高于假手术组(P<0.01);UDCA 60、120 mg/kg组大鼠脑梗死组织百分比均低于MCAO组(P<0.05)。MCAO组SOD含量低于假手术组,MDA含量高于假手术组(P<0.01);UDCA 60 mg/kg组、UDCA 120 mg/kg组SOD含量均高于MCAO组,UDCA 120 mg/kg组MDA含量均低于MCAO组(P<0.05)。MCAO组大鼠海马中PI3K、p-AKT蛋白表达低于假手术组(P<0.05);UDCA 60组、120 mg/kg组大鼠海马中PI3K、p-AKT蛋白表达高于MCAO组(P<0.05)。结论UDCA可能通过改善脑内氧化应激水平、调控AKT信号通路缓解脑缺血再灌注损伤。

Objective To study the protective effect and mechanism of ursodeoxycholic acid(UDCA)on cerebral ischemia-reperfusion injury in rats.Methods Forty male SD rats were divided into sham operation group,middle cerebral artery occlusion(MCAO)group,UDCA 60 mg/kg group,and UDCA 120 mg/kg group according to random number table method,with ten rats in each group.Rats were given prophylactic medicine for three days.MCAO model was established by thread bolt method.Reperfusion was realized after blocking for 1.5 hours.Rats continued to be given medicine for five days and half hour at the last administration,the neurological function score of rat was evaluated by Longa’s standard,2,3,5-triphenyltetrazolium chloride staining was used to calculate the volume of cerebral infarction in rats.The contents of superoxide dismutase(SOD)and malondialdehyde(MDA)in cerebral ischemic tissues of rats were measured.The expressions of PI3K and p-AKT proteins in rat hippocampus were detected.Results The neurological function score of MCAO group was higher than that of sham operation group(P<0.01).The neurological function scores of UDCA 60 mg/kg group and UDCA 120 mg/kg group were lower than those of MCAO group(P<0.05).In sham operation group,all brain tissues were rose red,and no infarct lesions were found;the cerebral infarction area of MCAO group showed obvious pale infarct area.The percentage of cerebral infarction in MCAO group was higher than that in sham operation group(P<0.01).The percentages of cerebral infarction tissue in UDCA 60 and 120 mg/kg groups were lower than those in MCAO group(P<0.05).The content of SOD in MCAO group was lower than that in sham operation group,and the content of MDA in MCAO group was higher than that in sham operation group(P<0.01).The contents of SOD in UDCA 60 and 120 mg/kg groups were higher than those in MCAO group,and the contents of MDA in UDCA 120 mg/kg groups were lower than those in MCAO group(P<0.05).The expressions of PI3K and p-AKT protein in hippocampus of MCAO group were lower than those of sham operation group(P<0.05).The expressions of PI3K and p-AKT protein in UDCA 60 and 120 mg/kg groups were higher than those in MCAO group(P<0.05).Conclusion UDCA has effects on the cerebral ischemia-reperfusion injury in rats,and its mechanism may be related to improvement of brain oxidative stress,regulating the AKT signaling pathway.