食源性肥胖大鼠弓状核神经肽Y和GnRH的变化及对卵泡发育的影响

The changes of NPY and GnRH in arcuate nuclcus and the effect of NPY and GnRH on the folliole of the diet-induced obese rats

目的观察食源性肥胖大鼠弓状核神经肽Y和促性腺激素释放激素(GnRH)的变化及对卵泡发育的影响,为肥胖所致不孕提供实验依据。方法刚断乳SD雌性大鼠,饲以自制高能饲料,喂养14周后,根据Lee’s指数及连续阴道涂片,筛选出肥胖不孕模型;另有饲普通饲料组为对照组。观察神经肽Y(NPY)、瘦素受体(ob-R)及促性腺激素释放激素(GnRH)在其下丘脑弓状核的表达情况,并测定血清雌二醇(E2)、睾酮(T)、瘦素(leptin)、卵泡刺激素(FSH)、黄体生成素(LH)的水平。结果肥胖不孕大鼠血清E2、T、leptin水平较对照组明显升高(P(0.05),FSH、LH水平较对照组明显降低(P(0.05);下丘脑弓状核NPY表达较对照组增强(P(0.05);ob-R及GnRH表达较对照组均减弱(P(0.05)。结论食源性肥胖大鼠由于神经内分泌-代谢失调引起NPY表达增强GnRH水平降低,导致下丘脑-垂体-卵巢轴功能失调性无排卵引起不孕。

Objective To investigate the changes of ncuropeptide Y（NPY）and GnRH in arcuate nucleu（ARC） and the effect of NPY and GnRH on the folliole of the diet-induced obese rats,and to assess the role of NPY and GnRH in the rat of diet-induced obesity.Methods To establish obese-infertile animal models by feeding the animals with high fat diet for 14 weeks.Expression patterns of NPY,OB-R and GnRH in arcuate nucleus of hypothalamic were observed and the levels of serum E2,T,leptin,FSH and LH in sera were evaluated.Results In model group,compared with the control group,serum E2,T and leptin levels were significantly elevated in tested group（P〈0.05）,whereas FSH and LH were decreased markedly（P〈0.05）.The expression of NPY in arcuate nucleus of hypothalamus was significantly high（P﹤0.05）;Contrary decreased expression of GnRH and ob-R were detected in the arcuate nucleus of obese-infertile rats（P〈0.05;P〈0.05）,when compared with the control group.Conclusion Up-regulation of NPY and down-regulation of GnRH expression in the ARC of the diet-induced obese rats consequently leads to infertility throw neuroendocrine metabolism disfunction.