饮食诱导肥胖抵抗大鼠食欲调节机制的研究

Liu Rong, Sun Chang-hao, Weng Ying

Department of Food Science and Engineering in Faculty of Forest Resourcer and Environment of Northeast Forestry University, Harbin 150040, China.

Zhonghua Yu Fang Yi Xue Za Zhi. 2005 Mar;39(2):119-21.

OBJECTIVE

To explore the cause of decreasing intake food of diet-induced obesity resistant (DIO-R) rats.

METHODS

Fifty male Sprague-dawley (SD) rats were randomly divided into control group and high-fat group and they were fed with basic diet and high-fat diet respectively for 13 weeks. DIO-R and diet-induced obesity (DIO) rats were selected according to their body weight and the quantity of energy intake, then observing the changes of the total food intake, the level of serum leptin and plasma NPY were determined by radioimmunoassay and the contents of the melanocortin receptor-4 (MCR-4) in brain were determined by Western Blot.

RESULTS

The total food intake of DIO-R rats was (1 679.1 +/- 146.8) g. The total food intake of DIO rats was (1 818.4 +/- 148.9) g. The total food intake of DIO-R rats was lower than that of DIO rats (P < 0.05). The level of plasma NPY of DIO-R rats was (795.24 +/- 83.59) ng/L. The level of plasma NPY of DIO rats was (1 007.14 +/- 172.83) ng/L. The level of plasma NPY of DIO-R rats was lower than that of the DIO rats (P < 0.05). The levels of serum leptin of basic, DIO-R and DIO rats was (4.80 +/- 0.75) microg/L, (9.17 +/- 1.19) microg/L and (9.32 +/- 1.04) microg/L. The level of serum leptin of rats in high-fat diet group was increased as compared with the rats in basic diet group, but there was no significant difference between DIO-R and DIO rats (P > 0.05). The levels of brain MCR-4 of basic, DIO-R and DIO rats were (342 +/- 31) mm2, (455 +/- 33) mm2, (355 +/- 30) mm2. High fat diets increased the content of brain MCR-4 in DIO-R rats.

CONCLUSION

DIO-R rats decreased appetite by increasing expression of ob gene to reduce activity of NPY pathway and activate the MCR-4 pathway, and thus inhibit the increase body of weight.

目的

探讨饮食诱导肥胖抵抗（DIO-R）大鼠进食量减少的原因。

方法

将50只雄性Sprague-dawley（SD）大鼠随机分为对照组和高脂组，分别给予基础饲料和高脂饲料喂养13周。根据体重和能量摄入量筛选出DIO-R大鼠和饮食诱导肥胖（DIO）大鼠，观察其总进食量的变化，采用放射免疫法测定血清瘦素水平和血浆神经肽Y（NPY）水平，采用蛋白质免疫印迹法测定脑组织中黑皮质素受体-4（MCR-4）的含量。

结果

DIO-R大鼠的总进食量为（1679.1±146.8）g，DIO大鼠的总进食量为（1818.4±148.9）g，DIO-R大鼠的总进食量低于DIO大鼠（P<0.05）。DIO-R大鼠血浆NPY水平为（795.24±83.59）ng/L，DIO大鼠血浆NPY水平为（1007.14±172.83）ng/L，DIO-R大鼠血浆NPY水平低于DIO大鼠（P<0.05）。基础组、DIO-R组和DIO组大鼠血清瘦素水平分别为（4.80±0.75）μg/L、（9.17±1.19）μg/L和（9.32±1.04）μg/L。高脂饮食组大鼠血清瘦素水平高于基础饮食组大鼠，但DIO-R大鼠与DIO大鼠之间无显著差异（P>0.05）。基础组、DIO-R组和DIO组大鼠脑组织MCR-4水平分别为（342±31）mm2、（455±33）mm2、（355±30）mm2。高脂饮食增加了DIO-R大鼠脑组织MCR-4的含量。