阴茎勃起神经递质CGRP蛋白表达的雄激素依赖性研究

目的 研究大鼠阴茎神经组织降钙素基因相关肽(CGRP)蛋白表达的雄激素依赖性。方法 64只雄性10周龄Sprague Dawley大鼠分为4组：A组为对照组，B组为去势组，C组为去势后肌注十一酸睾酮组，D组为喂饲保列治组。模型建立后分别在4周和10周处死部分大鼠，取腔静脉血和阴茎组织，应用放射免疫技术测定血睾酮(T)和二氢睾酮(DHT)浓度，应用免疫组化技术和计算机图象分析系统观察阴茎组织OGRP阳性神经纤维面积比例。结果 各实验组T和DHT含量低于对照组。4周时实验组和对照组阳性神经纤维面积比例的差异无统计学意义。10周时对照组阳性神经纤维面积比例明显高于实验组。各实验组4周模型和10周模型两两比较阳性神经纤维面积比例前者大于后者；对照组4周模型和10周模型阳性神经纤维面积比例无差异。结论 雄激素水平降低可引起大鼠阴茎神经组织CGRP蛋白表达下调，该影响有时间依从性。

Study of dependence of protein expression of calcitonin gene-related peptide on androgen in rat penis

Objective To study the dependence of protein expression of Calcitonin generdated peptide (CGRP) on androgens in the rat penile nerve fibers. Methods Sixty-four rats were divided into group A (intact controls),B (castrated),C (castrated but given testosterone undecanoate 25 mg/kg per month by intramuscular injection), and D (treated with finastride 4.5 mg/kg per day, orally). Then each group was divided into two subgroups: 4-weeks team(four weeks after treatment) and 10-weeks team (ten weeks after treatment). Immunohistochemical technique, radioimmunoassay and computer assisted quantitative image analysis system were used to observe the percent area of CGRP positive nerve fibers in rats penis. Results In 4-weeks-teams, there were no significant difference of the mean percent area of CGRP positive nerve fibers among group A and group B,C,D. (P=0.276,0.176,0.068). In 10-weeks teams, the mean percent areas of CGRP positive nerve fibers of experimental groups were lower than that of control group (P=0.000,0.000,0.000). In each experimental groups, the mean percent area of CGRP positive nerve fibers was higher in each 4-weeks-team than that in each 10-weeks-team(P=0.013,0.000,0.031), while in control group, there was no significant difference between 4 and 10 weeks models(P=0.579). Conclusions The protein expression of CGRP in the rat penile nervous tissue is dependent on androgen. Decrease of the serum level of androgen results in the lower experession of CGRP, and with the time passing, it becomes more distinct.