L-精氨酸与N-硝基-L-精氨酸单甲酯对雄性大鼠促性腺激素分泌的影响

目的 :阐明NO前体左旋精氨酸 (L arginine ,L Arg)和NO合酶的竞争性抑制剂N 硝基 L 精氨酸单甲基酯(Nω nitrio L arginine methyl ester,L NAME)对雄性性腺轴中腺垂体内分泌功能具有调节作用。　方法 :雄性SD大鼠分为 4组 ,每组 10只 ,分别于腹腔内注射L Arg、L NAME、L Arg +L NAME和生理盐水 ,1次 /d ,注射 4 8d ,首次剂量加倍 ;分别于注射前及注射后 1、4、8、13、2 4、3 6、4 8d在大鼠尾部采血 ,用放射免疫测定法测定血清中黄体生成素(LH)和卵泡刺激素 (FSH)的含量 ,对所得数据进行统计学处理。　结果 :L Arg对FSH和LH的分泌具有促进作用(P <0 0 1) ,而L NAME则抑制FSH和LH的分泌 (P <0 0 1) ,两者都具有时间依赖性。L Arg和L NAME混合注射时 ,其FSH和LH的含量与生理盐水注射组无区别 (P >0 0 5 )。　结论 :NO对雄性大鼠垂体促性腺激素的分泌具有促进作用。

Effects of L-NAME and L-Arg on the Release of Gonadotropin in vivo in Male Rat

Objectives: To determine if the endocrine of anterior pituitary in male reproductive axis was regulated by L-arginine(L-Arg, NO donor) and Nω -nitro-L-arginine-methyl-ester(L-NAME, NOS inhibitor). Methods: Forty male Sprague-Dawley rats(60～70 days)were divided into four groups, which were injected intraperitoneally with one of the following agents(once a day for 48 days, double dose was used at the first injection):①L-Arg; ②L-NAME; ③L-Arg+L-NAME; ④Normal saline. The blood samples were collected from the tail before injection and at the time of 1,4,8,13,24,36,48 days. The concentration of serum LH and FSH was measured by radioimmunoassay. The data statistics were processed with SPSS software. Results: L-Arg stimulated FSH and LH secretion(P<0 01). L-NAME suppressed FSH and LH secretion(P<0 01). Both were in a time dependent manner. Compared with control group, L-Arg injected simultaneously with L-NAME did not change concentration of serum LH and FSH(P>0 05). Conclusions: NO stimulates FSH and LH secretion in male rats.