高脂饮食诱导的非酒精性脂肪肝病大鼠IRS-1的表达

Expression of IRS-1 In the Non-alcoholic fatty liver rats induced by high-fat diet

目的:利用高脂饮食建立非酒精性脂肪性肝(NAFLD)的模型,探讨NAFLD大鼠肝脏胰岛素受体底物-1(IRS-1)的表达。方法:雄性SD大鼠30只,随机分成正常组和高脂组,分别给予普通饲料与高脂饲料,至8周末分别检测大鼠的体重、体长及生长状况;生化分析仪检测血生化指标;HE染色观察肝组织病理学变化;通过免疫组织化学方法和RT-PCR检测肝脏IRS-1蛋白和mRNA的表达。结果:高脂组的ALT、TC、TG显著高于正常组,差异有统计学意义(P<0.05)。予高脂饮食喂养8周后,高脂组大鼠肝脏符合NAFLD的病理特征。高脂组大鼠肝组织IRS-1较正常组表达显著下降,差异有统计学意义(P<0.01)。高脂组IRS-1的mRNA表达水平和蛋白表达一致。结论:高脂饮食喂养8周可使SD大鼠出现NAFLD,肝脏IRS-1的蛋白表达低于正常组。

Objective Non -alcoholic fatty liver （NAFL） model was induced by feeding the Sprague -Dawley （SD） rats with a high - fat diet. To investigate the expression of insulin Receptor substratc - 1 （ IRS - 1 ） in the liver of NAFL Method Thirty SD （N =30） young rats of 21 days were randomly divided into two groups,normal group （NG,n = 15 ） and high- fat feeding group （ HF, n = 15）. The rats of normal group were fed with common forage and those of the high - fat feeding group were given high - fat diet. Fifteen rats in each group were terminated at 8 week respectively. Their weight and growth condition were measured. Serum biochemical indexes were tested by biochemical analyzer. Observe the pathological changes of the liver tissue dynamically after Hematoxylin - eosin （HE） staining.＇Immunohistochemistry and RT- PCR methods were applied to detect the expression levels of IRS - 1 in liver tissue. Results Compared to the group, the alanine aminotransferase （ ALT）, triglyeeride （TG） and total cholesterol（ TC）levels in the HF group increased sigriificantly after 8 weeks ,the diference was statistically significant （P 〈0. 05 ）, the rats in the HF group were diagnosed with fatty liver disease. The liver tissue mRNA and protein levels of IRS - 1 were significantly reduced in HF group than in NG group, the difference was statistically significant （P 〈0. 01 ）. Conclusion High - fat diet may decrease NAFL in SD rats. The expression of IRS - 1 protein in the liver was lower in SD rats than that in NG.