社会应激后大鼠交配障碍的一个致病因素。

A causative factor of copulatory disorder in rats following social stress.

作者信息

Niikura Susumu, Yokoyama Osamu, Komatsu Kazuto, Yotsuyanagi Satoshi, Mizuno Tsu, Namiki Mikio

机构信息

Department of Urology, Kanazawa University School of Medicine, Kanazawa, Japan.

出版信息

J Urol. 2002 Aug;168(2):843-9.

PMID:12131378

Abstract

PURPOSE

We investigated the causative role of testosterone in copulatory disorder and the expression of c-fos messenger (m)RNA in the medial preoptic area in rats after social stress.

MATERIALS AND METHODS

To generate copulatory disorder rats in the experimental defeated group were attacked by residents for 10 minutes daily for 7 consecutive days (social stress). We then investigated the effect of repeat defeat on the frequency of mounting behavior and plasma testosterone levels. The effects of testosterone replacement and/or apomorphine (100 microg./kg. subcutaneously), a dopamine receptor agonist, on the frequency of mounting behavior were also studied. After experiencing social stress the brain area within the medial preoptic area was removed for analysis of c-fos and androgen receptor mRNA expression. Real-time reverse transcription-polymerase chain reaction was done to analyze gene expression.

RESULTS

Rats in the defeated group showed a reduced frequency of mounting behavior and a decrease in plasma testosterone levels compared with values in control rats (p <0.01). After testosterone replacement the frequency of mounting behavior became significantly higher than that of socially stressed rat (p <0.05) but did not achieve control levels. The frequency of mounting behavior by socially stressed rats after apomorphine treatment was significantly higher than that of vehicle treated rats (p <0.05) but the frequency produced by the combination of testosterone replacement and apomorphine injection did not achieve control levels. After the social stress experience c-fos mRNA expression was significantly increased compared with that in control rats (p <0.05). The expression of androgen receptor mRNA was not affected by social stress. Testosterone replacement significantly reduced the expression of c-fos mRNA in the medial preoptic area (p <0.05).

CONCLUSIONS

Our results indicate that a reduction in plasma testosterone may have a causative role in copulatory disorder induced by social stress. Changes in c-fos mRNA expression in the medial preoptic area correlated with copulatory disorder and, thus, they are suitable for monitoring that disorder.

摘要

目的

我们研究了睾酮在交配障碍中的致病作用以及社会应激后大鼠内侧视前区中c-fos信使核糖核酸（mRNA）的表达。

材料与方法

为制造交配障碍大鼠，实验性战败组大鼠连续7天每天被优势鼠攻击10分钟（社会应激）。然后我们研究重复战败对爬跨行为频率和血浆睾酮水平的影响。还研究了睾酮替代和/或阿扑吗啡（100微克/千克皮下注射），一种多巴胺受体激动剂，对爬跨行为频率的影响。经历社会应激后，取出内侧视前区内的脑区用于分析c-fos和雄激素受体mRNA的表达。进行实时逆转录聚合酶链反应以分析基因表达。

结果

与对照大鼠相比，战败组大鼠的爬跨行为频率降低且血浆睾酮水平下降（p<0.01）。睾酮替代后，爬跨行为频率显著高于社会应激大鼠（p<0.05），但未达到对照水平。阿扑吗啡治疗后社会应激大鼠的爬跨行为频率显著高于接受载体治疗的大鼠（p<0.05），但睾酮替代和阿扑吗啡注射联合产生的频率未达到对照水平。经历社会应激后，c-fos mRNA表达与对照大鼠相比显著增加（p<0.05）。雄激素受体mRNA的表达不受社会应激影响。睾酮替代显著降低内侧视前区中c-fos mRNA的表达（p<0.05）。