The aim of this study was to investigate the effects of a post-weaning isocaloric hyper-soybean oil diet on later obesity and explore the underlying mechanisms. In the present study, newborn male Wistar rats were weaned on d 24, divided into CON (control), HC and HSO groups. CON was assigned to AIN-93G diet (a hypercarbohydrate diet, for short HC diet) during the entire experiment. HC and HSO were fed with HC and isocaloric hyper-soybean oil (HSO) diet for 3 wk respectively, fed with HC diet for 2 wk successively, finally administrated high fat diet (HF) for 6 wk to induce obesity. On 3,5,11wk, the body weight, body fat content, blood glucose, blood lipid, serum insulin and leptin levels and obesity-related gene (CPT-1, FAS, UCP2, UCP3) expression levels in rats were detected. It was shown that body weight, body fat content, blood glucose and blood lipid, serum insulin and leptin levels in HSO were down-regulated on 3 and 5wk, therefore were significantly reduced on 11wk vs. HC. The CPT-1, UCP2, UCP3 gene expressions were up-regulated but FAS were down-regulated persistently in HSO. The study indicated that an early isocaloric HSO diet may reduce later obesity risk and reduce blood lipid and glucose abnormalities in adulthood via persistently influencing insulin and leptin sensitivity and permanent regulation of obesity-related gene expressions.

目的　探讨肥胖抵抗大鼠摄食量减少的原因。方法　采用50只健康雄性SD大鼠，分为对照组10只和高脂组40只，分别用基础饲料和高脂饲料喂养13周，然后根据体重和能量摄入量筛选出饮食诱导肥胖抵抗(DD-R)大鼠9只和饮食诱导肥胖(DD)大鼠10只，观察总摄食量的变化，放免法测定血清瘦素和血浆神经肽Y水平，免疫印迹法测定大鼠脑组织中黑色素皮质激素受体-4 (MCR24)蛋白含量。结果　DD-R大鼠总摄食量为(1679.1±146.8)g，明显低于DD大鼠的总摄食量(1818.4±148.9)g。DD-R大鼠血浆神经肽Y含量为(795.24±83.59)ng/L,显著低于DD大鼠(1007.14±172.83) ng/L；基础组大鼠血清瘦素含量为(4.80±0.75)μg/L, DD-R组为(9.17±1.19)μg/L， DD组为(9.32±1.04)μg/L,提示高脂饲料使大鼠血清瘦素水平明显增加，但DD-R与DD大鼠间无明显差别；基础组大鼠脑组织中MCR-4含量峰面积分析表明基础组为(342±31)mm2，DD-R组为(455±33)mm2，DD组为(355±30) mm2，说明高脂饲料使DD-R大鼠脑组织中MCR24含量增加。结论　DD-R大鼠通过增加ob基因的表达降低神经肽Y途径活性并激活MCR-4途径来减少进食量,从而抑制体重的增加。