Effects of dietary on hypothalamic neuropeptide Y gene expression and obesity in rats

  Objective   To explore the effect of high-fat diet on the hypo thalamic neuropeptide Y(NPY)expression and the mechanisms which predispose some individuals to become obese on high-fat diet.

  Methods   Thirty-six female SD rats were randomly divided into high-fat diet group(n=27)and chow fed control group(n=9).After 13 weeks of either a highfat diet or chew fed diet, the high-fat diet group was subdivided into Dietary Induced Obesity(DIO)and Dietary Induced Obesity Resistant(DIR)group according to the final body weight.Weight gain, food intake, and the concentration of plasma and hypothalamus neuropeptide Y were measured, and hypothalamic NPY mRNA expression were determined by RT-PCR.

  Results   The levels of body weight, caloric intake, and the ratio of plasma and hypothalamus NPY were significantly higher in DIO group than in DIR or control group(P < 0.01), while no significant difference was found between DIR and control group (P > 0.05);hypothalamic NPY mRNA were increased in DIO group but not in DIR than control group.

  Conclusion   On the High-fat diet, SD rats showed different susceptibility to obese and over eating, increased hypot halamic NPY were associated with their predispose to obese and over eating.