混合喂养法建立营养性肥胖大鼠模型

A Study of the Two-bottle-feeding Method in Establishing Diet Induced Obesity Rat Model

目的探讨用混合喂养法建立营养性肥胖大鼠模型。方法142只雄性断乳SD大鼠按照体重随机分为对照组(普通饲料喂养,n=40)和模型组(高脂饲料+普通饲料混合喂养,n=102),单笼饲养,每周记录动物体重、体长及摄食量。以普通饲料组lee’s index正常值上限-x+tν,α.s为肥胖确定标准,大于此上限为肥胖。结果(1)混合喂养法中,大鼠自主平衡营养,根据需要选择普通饲料,根据喜好选择高脂饲料,能量摄入及能量利用率显著高于对照组;(2)混合喂养法能有效促进大鼠摄入和利用能量。14周末肥胖个体为52只,肥胖率为51%。(3)模型组肥胖个体与非肥胖个体比较,前者摄食量显著高于后者,其中以高脂饲料摄入增多为主,普通饲料摄入无差异,对高脂饲料的偏好两者无显著差异,但能量利用率前者显著高于后者。(4)与对照组相比,模型组血浆高密度脂蛋白、甘油三酯均低于对照组,总胆固醇及低密度脂蛋白则高于对照,血糖水平无差异。模型组脂肪肝的发生率达100%。结论混合喂养法由动物自主择食,可摄取较多能量,是建立营养性肥胖大鼠模型的有效方法。

Objective To study the two-bottle-feeding method in modeling diet-induced obesity （DIO）. Methods 142 weaned Sprague-Dawley （SD） rats were housed individually and divided into two groups randomly according to their body weight, control （fed with CHOW, n = 40）, and model （two-bottle-feeding method, fed with high-fat diet and CHOW together, n = 102）. Body weight （BW）, body length （BL）, and food accumulations were measured weekly. The uper border x＋tv.a·s of lee＇s index （BW（g） ^1/3 × 1000/BL（cm）） of control was taken as criteria for obesity, individuals with values higher than that were definited as DIO. Results （1） In this method, animals balanced nutritent by themselves and chose chow according to needs and HF diet according to pleasure. The energy efficiency was higher in model than control. （2） This method facilieted the energy intake and utility by animals. According to lee＇s index, at the end of 14th week,51 percent rats were induced DIO. （3） Compared with DIO resistance individuals, the total food intake, HF diet intake and energy efficiency of DIO were much higher, but the chow intake and the preference to HF diet made no difference. （4） Compared with control,the plasma concentration of HDL-c,TG of model were lower than lhat of contral, while CHO, LDL-c were higher than that of control remarkablely, and the concentrations of blood glucose were the same between two groups. Besides, all the individuals in model developed fatty liver regardless obesity or resistance. Conclusions Two-bottle-feeding method is effective for modelling DIO in rats, through which the animals can choose different foods and take more energy by themselves.