Division of Life Science, Applied Life Science (Brain Korea 21 and EB-NCRC), Gyeongsang National University, Jinju, South Korea.
Neurosci Lett. 2010 Feb 26;471(1):25-9. doi: 10.1016/j.neulet.2010.01.002. Epub 2010 Jan 8.
Chronic exposure to ethanol suppresses the male reproductive activity which is primarily involved in the release of hypothalamic gonadotropin-releasing hormone (GnRH). The testicular GnRH and GnRH receptors (GnRH-R) are found in seminiferous tubules, which are predicted to act as a local regulator of spermatogenesis, although the function is not well known. In this study, we investigated the chronic ethanol effect on GnRH mRNA expression in hypothalamus and testis using in situ hybridization and RNase protection assay (RPA). The effect of ethanol on expressional changes of GnRH and GnRH-R mRNA was observed in adult and pubertal rats according to age and time from 2 weeks (short term) and 4 weeks (long term) periods. The results showed that GnRH mRNA expression in adult and pubertal rats was dramatically decreased in the testis while no significant change was observed in hypothalamus after both short and long term exposure to ethanol. The pubertal rats showed decrease in testicular GnRH and GnRH-R mRNA expression, whereas GnRH mRNA was increased significantly, while GnRH-R mRNA was further decreased after long term exposure in adults. This study suggested that chronic ethanol administration is more effective to testicular GnRH and GnRH-R mRNA expression than hypothalamus and causes a negative effect on the spermatogenesis process. Furthermore, our finding suggests that the deteriorative effects of ethanol on gonadal activity are more lethal in puberty than adults.
慢性暴露于乙醇会抑制男性生殖活动，而这主要涉及到下丘脑促性腺激素释放激素（GnRH）的释放。睾丸中的 GnRH 和 GnRH 受体（GnRH-R）存在于生精小管中，据预测它们可以作为精子发生的局部调节剂，尽管其功能尚不清楚。在这项研究中，我们使用原位杂交和核糖核酸酶保护分析（RPA）研究了慢性乙醇对下丘脑和睾丸中 GnRH mRNA 表达的影响。根据年龄和从 2 周（短期）和 4 周（长期）两个时间段开始，观察了乙醇对成年和青春期大鼠 GnRH 和 GnRH-R mRNA 表达变化的影响。结果表明，在短期和长期暴露于乙醇后，成年和青春期大鼠的睾丸中 GnRH mRNA 表达明显降低，而在下丘脑中没有观察到明显变化。青春期大鼠的睾丸 GnRH 和 GnRH-R mRNA 表达减少，而 GnRH mRNA 显著增加，而成年大鼠的 GnRH-R mRNA 进一步减少。这项研究表明，慢性乙醇给药对睾丸 GnRH 和 GnRH-R mRNA 表达的影响比下丘脑更有效，并对精子发生过程产生负面影响。此外，我们的发现表明，乙醇对性腺活动的恶化作用在青春期比成年期更为致命。
