高脂饮食致非酒精性脂肪肝大鼠血清瘦素水平的变化

Relationship Between Serum Leptin and Fatty Liver Induced by High-fat-diet in Rats

目的检测高脂饮食大鼠不同时期血清瘦素水平,研究瘦素在非酒精性脂肪肝病(NAFLD)发病机制中的作用和意义。方法66只大鼠随机分成正常组10只、高脂组56只。正常组予以普通饲料喂养,高脂组予以高脂饮食喂养,分别于4、8、12、16、20和24周末分批处死。用免疫放射法检测各组大鼠血清瘦素、胰岛素及c肽水平,HE染色观察肝脏病理变化,苏丹Ⅲ染色观察肝脏脂质蓄积情况。结果高脂饮食摄入成功建立大鼠脂肪肝模型。高脂组与正常组比较,血清瘦素、胰岛素、c肽水平、肝湿重及体重均显著升高(P<0.001),并随时间的延长而升高(P<0.01),瘦素与c肽及体重呈明显正相关(P<0.01),与胰岛素及肝湿重无明显相关性。结论高脂饮食摄入可使大鼠发生非酒精性脂肪性肝病,高脂组大鼠血清的瘦素、胰岛素和c肽水平升高,瘦素抵抗可能是脂肪肝发病的一个重要机制。

Objective To investigate the serum leptin level in fatty liver of rats induced by high - fat - diet and explore the effect of leptin on the mechanism of fatty liver. Methods Sixty - six SD male rats were divided into control group and fatty liver group in random,which was 10 and 56 respectively. Each rat was administered with general diet in control group while high- fat- diet in fatty liver group. The high -fat -diet was composed of lard（ 10% ） , cholesterin （2%） and general diet （78% ）. Rats of fatty group were killed in 4 w, 8 w, 12 w, 16 w, 20 w, 24 w in batches while these of control group were after 4 w. The serum leptin, insulin and c - peptide were detected by radioimmunoassay and pathological change were investigated by H - E stain and sudan Ⅲstain. Results Fatty liver model were successfully made by high - fat - diet in rats. Rats in fatty liver groups had higher levels of serum leptin, insulin, and c - peptide compared with control group, and these differences remained significant （P 〈 0.001 ）. In fatty groups, the serum level of leptin correlated well with the body weight and the serum level of c - peptide, but it did not correlate with the serum level of insulin and the weight of liver. Conclusions Our findings suggest that fatty liver can be induced by high - fat - diet in SD rats. The serum leptin concentrations are high in the fatty liver groups. Leptin resistance may be an important mechanism of fatty liver disease.