Faulkes C G, Abbott D H, Jarvis J U
MRC/AFRC Comparative Physiology Research Group, Institute of Zoology, London, UK.
J Reprod Fertil. 1991 Mar;91(2):593-604. doi: 10.1530/jrf.0.0910593.
To investigate possible anatomical and endocrine differences between breeding and non-breeding male naked mole-rats, 113 animals from 24 captive and 4 wild colonies were studied. While breeding males had larger reproductive tract masses compared to non-breeders relative to body mass (P less than 0.01), spermatogenesis was active in all of the non-breeding males examined histologically (n = 9) and spermatozoa were present in the epididymides. Compared with non-breeders, breeding males had significantly higher urinary testosterone concentrations (mean +/- s.e.m.: 23.8 +/- 2.3 vs 5.2 +/- 1.4 ng/mg Cr respectively; P less than 0.001), and plasma LH (10.7 +/- 1.7 vs 5.0 +/- 0.8 mi.u./ml respectively; P less than 0.01). Single doses of 0.1, 0.5 or 1.0 microgram GnRH produced a significant rise in plasma LH concentrations 20 min after s.c. injection in breeding and non-breeding males at all doses (P less than 0.001). However, there were differences in the magnitude of the LH response following administration of GnRH between breeding and non-breeding males, with non-breeding males showing a dose-response and having lower plasma LH concentrations 20 min after a single injection of 0.1 or 0.5 microgram (P less than 0.05), but not 1.0 microgram, GnRH. This apparent lack of pituitary sensitivity of non-breeding males to single doses of exogenous GnRH was reversed by 4 consecutive injections of 0.5 microgram GnRH at hourly intervals, suggesting that the reduced sensitivity may be the result of insufficient priming of the pituitary by endogenous GnRH. These results indicate that, despite the fact that non-breeding males were apparently producing mature gametes, clear endocrine deficiencies existed in male naked mole-rats.
为了研究繁殖期和非繁殖期雄性裸鼹鼠之间可能存在的解剖学和内分泌差异，对来自24个圈养群体和4个野生群体的113只动物进行了研究。与非繁殖雄性相比，繁殖雄性相对于体重而言生殖道质量更大（P小于0.01），但在所有经组织学检查的非繁殖雄性（n = 9）中精子发生活跃，附睾中存在精子。与非繁殖雄性相比，繁殖雄性的尿睾酮浓度显著更高（平均值±标准误：分别为23.8±2.3与5.2±1.4 ng/mg Cr；P小于0.001），血浆促黄体生成素（LH）也更高（分别为10.7±1.7与5.0±0.8 mi.u./ml；P小于0.01）。在繁殖期和非繁殖期雄性中，皮下注射0.1、0.5或1.0微克促性腺激素释放激素（GnRH）的单剂量后，20分钟时血浆LH浓度均显著升高（P小于0.001）。然而，繁殖期和非繁殖期雄性在给予GnRH后LH反应的幅度存在差异，非繁殖期雄性表现出剂量反应，在单次注射0.1或0.5微克（P小于0.05）而非1.0微克GnRH后20分钟时血浆LH浓度较低。非繁殖期雄性对单剂量外源性GnRH明显缺乏垂体敏感性，通过每小时连续注射4次0.5微克GnRH得以逆转，这表明敏感性降低可能是内源性GnRH对垂体启动不足的结果。这些结果表明，尽管非繁殖期雄性显然在产生成熟配子，但雄性裸鼹鼠仍存在明显的内分泌缺陷。
