建立雄性营养性肥胖幼鼠模型的研究

Diet-induced obesity animal model of impuberism in male rat

目的建立一种适合于研究儿童营养性肥胖的幼年大鼠肥胖模型。方法运用过度喂养造成高能量饮食新生大鼠肥胖模型,将出生第3天的雄性SD新生大鼠,随机分为对照组和模型组,模型组3只一笼,对照组10只一笼,分别由母鼠喂养至21 d,断乳后正常食料喂养,60 d后,随机6只一组,观察各组体质量、附睾及肾周脂肪质量,同时测定各组动物血糖、血脂、胰岛素等相关肥胖指标。结果出生21 d时,模型组较对照组体质量、体脂比、Lee′s指数明显增加(P<0.01或P<0.05,t值分别为-13.93,-5.12,-2.73,-4.87),血胰岛素分泌和胰岛素敏感指数均较对照组高(P<0.01,t值分别为-10.22,12.03),血糖和血脂无明显差异(P>0.05),出生后60 d,模型组较对照组体质量、体脂比、Lee′s指数明显增加(P<0.01,t值分别为-10.55,-5.53,-3.93,-5.99),血胰岛素分泌和胰岛素敏感指数、血糖和血脂均明显升高(P<0.01或P<0.05,t值分别为-2.26,-9.03,9.73,-5.47)。结论通过调整新生仔鼠只数,出生后21 d可诱导建立幼年雄性SD大鼠营养性肥胖模型,出生后60 d可建立幼年大鼠肥胖及代谢综合征模型。

Objective To establish the animal model of impuberism male rat with diet-induced obesity.Methods The impuberism model of male rat was established with early-onset obesity by overfeeding.On postnatal day 3,male pups were randomly distributed among the mothers.The litter size was adjusted to 10 newborns for normal feeding（control）or adjusted to three pups for overfeeding（model）.On postnatal day 21,rats of both groups were weaned and normally fed.Rats were measured for body weight,epididymal and perirenal fat weight,blood glucose,blood lipids,insulin and other related indicators 60 days later.Results There were significant increases in body weight,body fat,Lee′s index,the level of insulin secretion and insulin sensitivity indexes in the rats of model group than in the rats of control group on postnatal day 21（P〈0.01 or P〈0.05）.However,there were no differences in the levels of blood glucose and lipids between the two groups.There were significant increases in body weight,body fat,Lee′s index,the levels of blood glucose and lipids,insulin secretion and insulin sensitivity indexes in the rats of model group than in the rats of control group on postnatal day 60（P〈0.01 or P〈0.05）.Conclusion The obesity model of impuberism and the model of early-onset obesity and metabolic syndrome can be induced and established on postnatal day 21 and 60,respectively,by adjusting the numbers of newborn SD male rats.