高能量饮食对运动性动情周期抑制大鼠血清FSH、LH和下丘脑NPY mRNA水平的影响

目的:探讨高能量饮食对运动性动情周期抑制大鼠血清促卵泡激素(FSH)、黄体生成素(LH)和下丘脑组织神经肽Y(NPY)mRNA水平的影响。方法:选用健康、成熟的2月龄雌性SD大鼠24只,随机分为3组:安静对照组(C组)8只,递增负荷训练组(T组)8只,递增负荷训练+营养干预组(Tn组)8只。C组大鼠和T组大鼠用基础饲料喂养,能量摄入为570kJ/只/天。Tn组大鼠用高能量饲料喂养,能量摄入为710kJ/只/天。训练组进行6周递增负荷训练。实验结束后,采用放射免疫法测定各组大鼠血清FSH和LH浓度;用反转录聚合酶链反应法测定下丘脑NPYmRNA水平。结果:T组大鼠血清FSH浓度和FSH/LH比值均显著高于C组(P<0.01),其下丘脑NPYmRNA相对表达量显著低于C组(P<0.01)。Tn组大鼠血清FSH浓度与FSH/LH比值均显著低于T组(P<0.01),其下丘脑NPYmRNA相对表达量显著高于T组(P<0.01)。结论:(1)持续递增负荷训练可导致大鼠卵巢功能低落及下丘脑NPYmRNA水平降低。(2)本研究采用的高能量饮食可以改善运动性动情周期抑制大鼠卵巢功能,维持下丘脑NPYmRNA水平。

Effect of High-Energy Diet on the Serum FSH, LH and NPY mRNA Levels in Exercising Rats with Estrous Cycle Inhibition

Objective To investigate the effect of high-energy diet on the serum follicle stimulating hormone (FSH),luteinizing hormone(LH)and hypothalamic neuropeptide Y(NPY)mRNA levels in exercising rats with estrous cycle inhibition. Methods Twenty-four adult and healthy female SD rats were randomly divided into 3 groups:group C (sedentary,fed with common rodents animal forage,and energy intake was 570 kJ per rat per day),group T(6-week incremental graded exercise,fed with common rodents animal forage,and energy intake was 570 kJ per rat per day) and group Tn(6-week incremental graded exercise,fed with high-energy diet,and energy intake was 710 kJ per rat per day). The levels of serum FSH and LH were measured by radioimmunoassay 6 weeks later. The levels of NPY mRNA were measured by RT-PCR. Results The serum FSH concentration and FSH/LH ratio in group T were higher than that in group C(P<0.01)and the NPY mRNA/GAPDH mRNA gray scale ratio in group T was lower than that in group C(P< 0.01). The serum FSH concentration and FSH/LH ratio in group Tn were lower than that in group T(P <0.01),and the NPY mRNA/GAPDH mRNA gray scale ratio was significantly higher than that in Group T(P <0.01). Conclusion Suppression of ovarian function and the decreased hypothalamic NPY mRNA level in group T were associated with the incremental intensity of exercise. The high-energy diet employed in this study could improve ovarian function and maintain the level of hypothalamic NPY mRNA in exercising rats with estrous cycle inhibition.