Kuwahara S, Mizukami T, Omura M, Hagihara M, Iinuma Y, Shimizu Y, Tamada H, Tsukamoto Y, Nishida T, Sasaki F
Department of Veterinary Anatomy, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Osaka, Japan.
Anat Rec. 2000 Dec 1;260(4):366-72. doi: 10.1002/1097-0185(20001201)260:4<365::AID-AR50>3.0.CO;2-M.
Seasonal changes in the hypothalamo-pituitary-testes axis of the Japanese wood mice (Apodemus speciosus) were studied. The testes, epididymis, pituitary and hypothalamus were compared between mice in the breeding season (July) and non-breeding season (October) using morphological techniques, and the plasma testosterone level was evaluated by enzyme immunoassay. Significant differences in these tissues were observed between the breeding season and the non-breeding season. Specifically, differences in the non-breeding season included 1) a decline in testicular and epididymal weights, arrest of spermatogenesis and decrease of serum testosterone concentration; 2) a decrease in the number of luteinizing hormone (LH)-, follicle stimulating hormone (FSH)-, prolactin (PRL)-, and growth hormone (GH)-immunoreactive cells, and decrease in the size of FSH, PRL, and GH-immunoreactive cells; and 3) an increase in the size of gonadotropin-releasing hormone (GnRH)-immunoreactive neurons. Our findings indicate that the male adult Japanese wood mouse exhibits unique seasonal changes in the hypothalamo-pituitary-testes axis which are not found in laboratory mice.
对日本林姬鼠（Apodemus speciosus）下丘脑-垂体-睾丸轴的季节性变化进行了研究。利用形态学技术，比较了繁殖季节（7月）和非繁殖季节（10月）小鼠的睾丸、附睾、垂体和下丘脑，并通过酶免疫测定法评估血浆睾酮水平。在繁殖季节和非繁殖季节之间观察到这些组织存在显著差异。具体而言，非繁殖季节的差异包括：1）睾丸和附睾重量下降、精子发生停滞以及血清睾酮浓度降低；2）促黄体生成素（LH）、促卵泡激素（FSH）、催乳素（PRL）和生长激素（GH）免疫反应性细胞数量减少，以及FSH、PRL和GH免疫反应性细胞大小减小；3）促性腺激素释放激素（GnRH）免疫反应性神经元大小增加。我们的研究结果表明，成年雄性日本林姬鼠在下丘脑-垂体-睾丸轴上表现出独特的季节性变化，而这些变化在实验室小鼠中未被发现。
