Faulkes C G, Abbott D H, Jarvis J U
MRC/AFRC Comparative Physiology Research Group, Institute of Zoology, Regent's Park, London, UK.
J Reprod Fertil. 1990 Mar;88(2):559-68. doi: 10.1530/jrf.0.0880559.
To investigate the endocrine cause of reproductive suppression in nonbreeding female naked mole-rats, animals from 35 colonies were studied in captivity. Urinary and plasma progesterone concentrations were elevated in pregnant females (urine: 10.0-148.4 ng/mg Cr, 27 samples from 8 females; plasma: 3.6-30.0 ng/ml, 5 samples from 5 females; Days 21-40 of pregnancy) and cyclic breeding females (urine: 0.5-97.8 ng/mg Cr, 146 samples from 7 females; plasma: less than 1.0-35.4 ng/ml, 25 samples from 7 females). The latter group showed cyclic patterns of urinary progesterone, indicating a mean ovarian cycle length of 34.4 +/- 1.6 days (mean +/- s.e.m.) with a follicular phase of 6.0 +/- 0.6 days and a luteal phase of 27.5 +/- 1.3 days (19 cycles from 9 breeding females). In non-breeding females urinary and plasma progesterone values were undetectable (urine: less than 0.5 ng/mg Cr, 232 samples from 64 females; plasma: less than 1.0 ng/ml, 7 samples from 6 females). Breeding females had higher (P less than 0.001) plasma LH concentrations (3.0 +/- 0.2 mi.u./ml, 73 samples from 24 females) than did non-breeding females (1.6 +/- 0.1 mi.u./ml, 57 samples from 44 females). Urinary and plasma progesterone concentrations in non-breeding females from wild colonies situated near Mtito Andei, Kenya, were either below the assay sensitivity limit (urine: less than 0.5 ng/mg Cr, 11 females from 2 colonies; plasma: less than 1.0 ng/ml, 25 females from 4 colonies), or very low (plasma: 1.6 +/- 0.6 ng/ml, 15 females from 4 colonies). In captivity, non-breeding females removed from their colonies (i.e. the dominant breeding female) and either paired directly with a non-breeding male (N = 2), or removed and housed singly for 6 weeks before pairing with a non-breeding male (N = 5) may develop a perforate vagina for the first time in as little as 7 days. Urinary progesterone concentrations rose above 2.0 ng/mg Cr (indicative of a luteal phase) for the first time 8.0 +/- 1.9 days after being separated. These results suggest that ovulation is suppressed in subordinate non-breeding female naked mole-rats in captive and wild colonies, and show that plasma LH concentrations are significantly lower in these non-breeding females. This reproductive block in non-breeding females is readily reversible if the social factors suppressing reproduction are removed.
为了研究非繁殖期雌性裸鼹鼠生殖抑制的内分泌原因，对来自35个群体的动物进行了圈养研究。怀孕雌性（尿液：10.0 - 148.4 ng/mg肌酐，来自8只雌性的27个样本；血浆：3.6 - 30.0 ng/ml，来自5只雌性的5个样本；怀孕第21 - 40天）和周期性繁殖雌性（尿液：0.5 - 97.8 ng/mg肌酐，来自7只雌性的146个样本；血浆：小于1.0 - 35.4 ng/ml，来自7只雌性的25个样本）的尿液和血浆孕酮浓度升高。后一组显示出尿液孕酮的周期性模式，表明平均卵巢周期长度为34.4±1.6天（平均值±标准误），卵泡期为6.0±0.6天，黄体期为27.5±1.3天（来自9只繁殖雌性的19个周期）。在非繁殖雌性中，尿液和血浆孕酮值无法检测到（尿液：小于0.5 ng/mg肌酐，来自64只雌性的232个样本；血浆：小于1.0 ng/ml，来自6只雌性的7个样本）。繁殖雌性的血浆促黄体生成素（LH）浓度（3.0±0.2 mi.u./ml，来自24只雌性的73个样本）高于非繁殖雌性（1.6±0.1 mi.u./ml，来自44只雌性的57个样本）（P小于0.001）。位于肯尼亚姆蒂托安代伊附近野生群体中的非繁殖雌性的尿液和血浆孕酮浓度要么低于检测灵敏度极限（尿液：小于0.5 ng/mg肌酐，来自2个群体的11只雌性；血浆：小于1.0 ng/ml，来自4个群体的25只雌性），要么非常低（血浆：1.6±0.6 ng/ml，来自4个群体的15只雌性）。在圈养环境中，从群体中移出的非繁殖雌性（即占主导地位的繁殖雌性），要么直接与一只非繁殖雄性配对（N = 2），要么在与一只非繁殖雄性配对前移出并单独饲养6周（N = 5），可能在短短7天内首次出现阴道穿孔。分离后8.0±1.9天，尿液孕酮浓度首次升至2.0 ng/mg肌酐以上（表明处于黄体期）。这些结果表明，在圈养和野生群体中，从属的非繁殖雌性裸鼹鼠排卵受到抑制，并且表明这些非繁殖雌性的血浆LH浓度显著较低。如果去除抑制繁殖的社会因素，非繁殖雌性的这种生殖阻滞很容易逆转。
