Norris D O, Norman M F, Pancak M K, Duvall D
Gen Comp Endocrinol. 1985 Oct;60(1):51-7. doi: 10.1016/0016-6480(85)90291-6.
Significant seasonal changes were observed in spermatogenesis, testicular weights, vasa deferentia, and cloacal development as well as in plasma androgen levels (testosterone and dihydrotestosterone). Androgen levels were highest in the fall and lowest during the period of spermatogenesis. Low levels of androgens were also observed during the breeding season. Diameter of the vasa deferentia corresponded to presence of stored spermatozoa and not to plasma androgen levels. Testicular weights were independent of androgen levels and stage of spermatogenesis. Maximal testicular weight occurred at the onset of spermiation. Hypertrophy of the epithelial lining of the vasa deferentia and the condition of the cloacal gland complex were correlated closely to plasma androgen levels. Comparison of spermatogenetic events, androgen-dependent sex accessory structures, and plasma androgen levels suggests either differential release of pituitary gonadotropins on a seasonal basis or variable testicular responsiveness to gonadotropins.
在精子发生、睾丸重量、输精管和泄殖腔发育以及血浆雄激素水平（睾酮和双氢睾酮）方面观察到显著的季节性变化。雄激素水平在秋季最高，在精子发生期间最低。在繁殖季节也观察到低水平的雄激素。输精管直径与储存精子的存在相关，而与血浆雄激素水平无关。睾丸重量与雄激素水平和精子发生阶段无关。最大睾丸重量出现在精子释放开始时。输精管上皮衬里的肥大和泄殖腔腺复合体的状况与血浆雄激素水平密切相关。对精子发生事件、雄激素依赖性性附属结构和血浆雄激素水平的比较表明，要么是垂体促性腺激素在季节性基础上的差异释放，要么是睾丸对促性腺激素的反应性变化。
