高能高脂与限能高脂饮食对大鼠糖脂代谢及胰腺β细胞的影响

The effect of high-energy high-fat and calorie-restricted high-fat diet on glucose and lipid metabolism and pancreatic β cell in SD rats

目的观察高能高脂与限能高脂饮食对大鼠糖脂代谢及胰腺β细胞的影响。方法 36只雄性SD大鼠随机分为普通饮食组(ND组)、高能高脂组(HD组)和限能高脂组(LHD组)。喂养12周后,比较各组大鼠糖脂代谢情况,应用高葡萄糖-正胰岛素钳夹技术评价胰腺β细胞功能,应用原位末端标记法(TUNEL法)检测胰岛内的细胞凋亡情况。结果 HD组大鼠体重显著高于ND组及LHD组(P<0.05)。各组大鼠的空腹血糖(fasting blood glucose,FBG)水平差异无统计学意义(P>0.05);HD组大鼠的总胆固醇(total cholesterol,TC)、空腹胰岛素(fasting insulin,FINS)、低密度脂蛋白胆固醇(low-density lipoprotein cholesterol,LDL-C)、胰岛素抵抗指数(HOMA insulin resistance index,HOMA-IR)明显高于ND组,三酰甘油(triglyceride,TG)明显高于ND组和LHD组,差异均有统计学意义(P<0.05);LHD组大鼠除TG和HOMA-IR明显高于ND组外(P<0.05),余指标的组间比较差异无统计学意义(P>0.05)。高葡萄糖-正胰岛素钳夹试验结果显示,HD组大鼠的葡萄糖输注率(glucose infusion rate,GIR)明显低于LHD组及ND组(P<0.05),HD组和LHD组大鼠的胰岛素分泌则明显低于ND组(P<0.05)。HD组和LHD组大鼠的胰岛细胞萎缩和凋亡较ND组更为明显。结论高能高脂饮食可诱导大鼠出现肥胖、脂代谢异常、胰岛素抵抗以及胰岛细胞凋亡增加。限能高脂饮食虽未诱导大鼠出现肥胖及脂代谢异常,但依然引起胰岛素抵抗及胰岛细胞凋亡增加。

Objective To observe the influence of high-energy high-fat and calorie-restricted high-fat diet on glucose and lipid metabolism and pancreatic β cell in SD rats. Methods A total of 36 male SD rats were randomly divided into normal diet （ND） group, high-energy high-fat diet （HD） group and calorie-restricted high-fat diet （LHD） group. Glucose and lipid metabolism were measured after 12 weeks. Pancreatic β cell function was evaluated by hyperglycemic clamps test and the apoptosis of islet cells was determined by TUNEL test. Results The weight of rats in HD group were significantly higher than those in ND and LHD group. There was no significant difference in the fasting blood glucose （FBG） level of ND, HD and LHD group （P〉0.05）. Total cholesterol （TC）, fasting insulinlevel （FINS）, low-density lipoprotein cholesterol （LDL-C） and HOMA insulin resistance index （HOMA-IR） of the rats in HD group were all significantly higher than those in ND and LHD group （P d0.05）. Triglycerides （TG） and HOMA-IR of the rats in LHD group were significantly higher than those in ND group （P〈0.05）. The results of the hyperglycemic clamps test showed that the glucose infusion rate GIR of the rats in HD group was significantly lower than that in LHD and ND group （P 〈0.05）. However,insulin secretion rate of the rats in HD and LHD group was significantly lower than that in ND group （P〈0.05）. The apoptosis of islet cells in HD and LHD group were more serious than that in ND group. Conclusions Obesity,dyslipidemia,insulin resistance and cell apoptosis could be induced by high-energy high-fat diet of 12 weeks in SD rats. Calorie restricted high-fat diet could not induce obesity and dyslipidemia,while it could induce insulin resistance and cell apoptosis in SD rats.