高脂饮食和地塞米松联合诱导胰岛素抵抗大鼠模型

目的用高脂饲料＋地塞米松（dexamethasone,DEX）隔日腹腔注射建立实验性胰岛素抵抗大鼠模型,研究该模型糖代谢、脂代谢和激素水平等方面的变化。方法采用Wistar雄性大鼠,分为正常对照组、高脂组、DEX组（1mg/kg,i.p.）和高脂＋DEX组（1mg/kg,i.p.）,连续观察8周,每周测定大鼠空腹血糖,分别于造模第2周和第8周测糖耐量,8周后处死大鼠,测定胸腺、脾脏、肝脏等脏器重量。结果高脂饲料能加重腹腔注射DEX造成的空腹血糖升高,造模第8周空腹血糖（7.7±0.7）较空白组（6.5±0.6）显著升高。使模型动物糖耐量明显异常,肝糖原、肌糖原含量显著增加,血浆胰岛素及游离脂肪酸水平显著升高,各脏器指数明显增加。结论高脂＋DEX隔日腹腔注射能成功诱导胰岛素抵抗大鼠模型,这种造模方法较单纯注射DEX或单纯高脂饲养成模率高,造模周期短。

Insulin-Resistant Rat Model induced by High-Fat Feeding and Dexamethasone

Objective To induce an insulin-resistant （IR） animal model and investigate the effects of glucocorticoid and high-fat feeding on plasma glucose, glucose tolerance test （GTF） ,lipid level, hepatic glycogen content, muscle glycogen content and plasma insulin level in the insulin-resistant rats. Methods The insulin resistance model was induced by high-fat feeding, dexamethasone （DEX） and high-fat feeding plus DEX in rats, respectively. Normal male rats were divided into control group, highfat feeding model group, DEX-treated group and high-fat feeding plus DEX group, 10 rats in each group. Several parameters in the rats were measured. Results The plasma glucose level, glucose tolerance test （GRIT）, plasma insulin level, hepatic glycogen content, muscle glycogen content and FFA in both high-fat feeding group and DEX-treated groups were significantly increased compared with those of normal control group. Those changes were most significant in the rats of high-fat feeding plus DEX group. Conclusion Dexamethasone can induce insulin resistance, high-fat feeding can aggravate the effect induced with DEX. High-fat feeding and DEX together can be reliably and conveniently used to induce a insulin-resistant IR rat model.