补充牛磺酸对高脂饮食C57BL/6J小鼠糖脂代谢的影响

Effects of Taurine Supplementation on Glycolipid Metabolism in C57BL/6J Mice with High-fat Diet

【目的】通过建立高脂动物模型,探究牛磺酸对肥胖小鼠糖脂代谢的影响。【方法】将20只5周龄SPF级C57BL/6J雄性小鼠随机分为4组:空白组、模型组、3%牛磺酸组和5%牛磺酸组,每组5只,试验期为15周。空白组小鼠饲喂对照饲粮,模型组饲喂高脂饲粮,其余两组在模型组饲粮的基础上分别添加3%、5%的牛磺酸。试验结束前2周分别进行口服葡萄糖耐受实验(OGTT)和胰岛素耐受实验(ITT)。试验结束后乙醚麻醉眼球取血,采用颈椎脱臼法处死小鼠,采集肝脏、肾脏、脾脏、附睾脂肪组织并称重,计算脏器/脂肪系数。测定血清中各项生化指标及瘦素(LEP)、脂联素(ADPN)含量,以及肝脏中甘油三酯(TG)、总胆固醇(TC)的含量,采用油红O染色和苏木精-伊红(HE)染色分别观察肝脏脂滴分布和脂肪组织形态变化。【结果】(1)与空白组相比,模型组小鼠体重极显著增加(P<0.01),血糖(GLU)及血脂指标出现异常,葡萄糖耐受和胰岛素耐受的曲线下面积极显著升高(P<0.01),符合肥胖模型的特征。(2)与模型组相比,添加牛磺酸后小鼠总增重、肝脏系数和脂肪系数均极显著降低(P<0.01);血清中丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)活性及低密度脂蛋白(LDL)含量极显著升高(P<0.01),GLU含量显著下降(P<0.05);肝脏中TG和TC含量极显著下降(P<0.01),ADPN含量极显著升高(P<0.01);葡萄糖耐受和胰岛素耐受的曲线下面积均极显著降低(P<0.01);肝脏中的脂滴数量减少,脂肪细胞的细胞截面积极显著减小(P<0.01),细胞数量极显著增多(P<0.01),脂肪细胞分布较均匀。【结论】牛磺酸可通过调节高脂饮食诱导的肥胖小鼠糖脂代谢水平,改善其肝脏及脂肪的组织病理形态,可能对肝脏具有保护作用。

【Objective】 The experiment was conducted to study the effect of taurine on glucose and lipid metabolism in obese mice induced by high-fat diet.【Method】 20 SPF C57 BL/6 J male mice aged 5 weeks were randomly divided into 4 groups(blank, model, 3% taurine and 5% taurine groups) with 5 mice in each group.The experiment lasted for 15 weeks.The mice in blank group were fed a control diet, the mice in model group were fed a high-fat diet, and the mice in other two groups were supplemented with 3% and 5% taurine respectively on the basis of the model group diet.Oral glucose tolerance test(OGTT) and insulin tolerance test(ITT) were performed 2 weeks before the end of the trial.At the end of the experiment, the eyeballs were anesthetized with ether and blood was collected.The mice were sacrificed by cervical dislocation and the liver, kidney, spleen and epididymal adipose tissue were collected and weighed to calculate the organ/fat coefficient.The serum biochemical indexes and the contents of leptin(LEP) and adiponectin(ADPN),triglyceride(TG) and total cholesterol(TC) in liver were determined.Oil red O staining and hematoxylin-eosin(HE) staining were used to observe the distribution of lipid droplets and the morphological changes of adipocytes in liver.【Result】(1)Compared with blank group, the body weight of mice in model group was extremely significantly increased(P<0.01),and the indexes of blood glucose(GLU) and blood lipids were abnormal.The glucose tolerance and insulin tolerance increased extremely significantly under the curve(P<0.01),which was consistent with the characteristics of the obesity model.(2)Compared with model group, the total weight gain, liver coefficient and fat coefficient of taurine supplementation were extremely significantly decreased(P<0.01),the activities of alanine aminotransferase(ALT),aspartate aminotransferase(AST) and content of low density lipoprotein(LDL) in serum were extremely significantly increased(P<0.01),while the content of GLU was significantly decreased(P<0.05). The contents of TG and TC in liver were extremely significantly decreased(P<0.01),the content of ADPN was extremely significantly increased(P<0.01),glucose tolerance and insulin tolerance were positively and extremely significantly decreased under the curve(P<0.01). The number of lipid droplets in liver decreased, and the cross section of adipocytes decreased extremely significantly(P<0.01),the number of adipocytes increased extremely significantly(P<0.01),and the distribution of adipocytes was uniform.【Conclusion】 Taurine might have a protective effect on liver by regulating glucose and lipid metabolism and improving histopathological morphology of liver and fat in obese mice induced by high-fat diet.