生长激素补充对老龄大鼠勃起功能及阴茎海绵体nNOS表达的影响

目的探讨生长激素(GH)补充对老龄大鼠勃起功能及阴茎海绵体神经型一氧化氮合酶(nNOS)表达的影响。方法20只18月龄SD大鼠随机均分成A、B两组,10只2月龄SD大鼠为C组。A组给予GH1U/(kg·d),B、C组给予相同剂量的生理盐水,均皮下注射8周。于8周末观察阿朴吗啡(APO)皮下注射与大鼠海绵体内注射罂粟碱诱导的阴茎勃起情况,并用免疫组化SP法检测阴茎海绵体组织中nNOS神经纤维的数目。结果8周末时,A、C组大鼠APO诱导的勃起次数、海绵体内注射罂粟碱诱导的最大海绵体内压以及阴茎海绵体组织中nNOS神经纤维数目均显著高于B组(P<0.05或P<0.01)。结论老龄大鼠勃起功能及阴茎海绵体nNOS表达较成年大鼠明显下降,GH补充可以部分改善老龄大鼠的勃起功能,其机制之一可能与GH补充增加了老龄大鼠阴茎海绵体组织中nNOS神经纤维数目有关。

Effects of Growth Hormone Supplementation on Erectile Function and Expression of nNOS in Aging Rats

OBJECTIVE: To explore the effects of growth hormone( GH) supplementation on erectile function and expression of nNOS in the intracavernosal nerves in aging rats. METHODS: Twenty male Sprague-Dawley rats aged 18 months were randomly divided into Groups A and B, and ten 2-month-old male Sprague-Dawley rats included in Group C. 1 U/(kg x d) GH was given to Group A, and the same volume of saline to Groups B and C. After 8 weeks of treatment, evaluation was made of the erections induced by apomorphine (APO), maximal intracavernous pressure (ICP) induced by intracavernous papaverine injection and expression of nNOS in the intracavernosal nerves by streptavidin-peroxidase immunohistochemical techniques. RESULTS: After 8 weeks of treatment, the erection frequency, maximal ICP and expression of nNOS in the intracavernosal nerves of the rats in Groups A and C were significantly higher than those in Group B (P < 0.05 or P < 0.01). CONCLUSION: Growth hormone supplementation can improve the erectile function of aging rats, which may be attributed to the increase in the expression of nNOS in the intracavernosal nerves.