Maurel D, Lacroix A, Boissin J
Acta Endocrinol (Copenh). 1984 Jan;105(1):130-8. doi: 10.1530/acta.0.1050130.
The annual cycle of the testicular function (testis and epididymis weights and plasma testosterone levels) were considered in relation to seasonal variations in plasma LH and prolactin concentrations in two wild European mammals: the badger and the fox. Phase relationships were established between the annual prolactin cycles and daylight duration. The influence of castration on the seasonal variations in plasma LH levels was also studied. The resumption of activity in the testicular function occurs during autumn for both species. The reproduction period begins in winter but it is over by the beginning of spring for the fox whereas for the badger it lasts until early summer. In the same way, the annual cycle of the gonadotrophic function which, in the fox, presents only one maximum at the end of autumn, is bimodal in the badger with one maximum in January and a second in June. On the other hand, both species have a similar annual prolactin cycle, which shows an increase from the winter solstice onwards, in synchronization with the increase in daily light duration. The highest prolactin levels are measured in spring followed by a decrease during summer. This result calls into question the role played by prolactin in the regulation of the testicular function in as far as the two species have an annual reproductive cycle of the 'short-day' type (onset of activity occurring before the winter solstice) but show seasonal prolactin variations similar to those described for 'long-day' species.
在两种欧洲野生哺乳动物獾和狐狸中，研究了睾丸功能的年度周期（睾丸和附睾重量以及血浆睾酮水平）与血浆促黄体生成素（LH）和催乳素浓度的季节性变化之间的关系。确定了年度催乳素周期与日照时长之间的相位关系。还研究了去势对血浆LH水平季节性变化的影响。两种动物的睾丸功能在秋季恢复活动。繁殖期始于冬季，但狐狸的繁殖期在春季初结束，而獾的繁殖期持续到初夏。同样，促性腺功能的年度周期在狐狸中仅在秋末出现一个峰值，而在獾中则呈双峰，1月出现一个峰值，6月出现第二个峰值。另一方面，两种动物都有相似的年度催乳素周期，从冬至开始升高，与日照时长的增加同步。春季测得的催乳素水平最高，随后在夏季下降。这一结果对催乳素在睾丸功能调节中所起的作用提出了质疑，因为这两种动物具有“短日照”型的年度繁殖周期（活动开始于冬至之前），但其催乳素的季节性变化却与描述的“长日照”物种相似。
