Abstract: To study the weight loss mechanism of soy isoflavone dependent on leptin.In the present study,the food-induced obese rats model was established treated with low,medium and high dose soy isoflavone,to investigate the effects of soy isoflavone on body mass,morphology of fat cell inside the abdomen,expression of α-MSH、POMC mRNA、Ob-Rb mRNA in the hypothalamic arcuate nucleus and pituitary,by weighting every week,Sudan Ⅲ staining,immunohistochemical and in situ hybridization analysis.The results showed α-MSH abundantly expressed in the arcuate nucleus,neurohypophysis and pars intermedia,POMC mRNA rarely expressed in the arcuate nucleus and pituitary,and Ob-Rb mRNA only expressed in the arcuate nucleus,simultaneously the three factors were significantly less present in fat rats.After treated with soybean isoflavones,the body weight of obese rats decreased,the area of abdominal fat cells reduced and distribution improved significantly,also the expression of α-MSH,POMC mRNA,Ob-Rb mRNA increased,which could be positively correlated with the dose.Results suggested that soy isoflavone might reduce fat storage and stimulated Ob-Rb expression,then promoted production of POMC and α-MSH,thus improve the state of leptin resistance in rats,and cause weight loss.

Key words: Soy isoflavone, Obese rat, Immunohistochemistry, Hybridization situ, α-MSH, POMC, Ob-Rb

CLC Number: 

• Q78

• S565.03