O'Byrne K T, Lunn S F, Dixson A F
MRC Reproductive Biology Unit, Centre for Reproductive Biology, Edinburgh.
J Endocrinol. 1988 Aug;118(2):259-64. doi: 10.1677/joe.0.1180259.
Stressful stimuli associated with aggressive encounters and low social rank may affect female fertility in a variety of mammalian species. In these experiments we examined the effects of aggressive encounters and physical restraint in a primate chair on the patterns of LH secretion in ovariectomized, oestrogen-primed female marmosets. Receipt of aggression from a female conspecific, followed by physical restraint for collection of blood samples (at 10-min intervals for 4 h), resulted in marked declines in LH concentrations during oestradiol-induced LH surges in five animals (from 112 +/- 24 micrograms/l to 45 +/- 12 micrograms/l; group means +/- S.E.M.; P less than 0.05). This was due to reductions in LH pulse amplitude rather than to changes in pulse frequency. Decreases in plasma concentrations of LH were reversed by treating females with exogenous LH-releasing hormone (LHRH). Cortisol treatment had no effect on LH levels during oestrogen-induced LH surges. Effects of aggressive encounters and physical restraint on plasma LH were not therefore due to reduced pituitary responsiveness to LHRH or to increased plasma concentrations of cortisol. In separate experiments it was found that physical restraint alone had no effect on plasma LH in habituated subjects, and that decreases in plasma LH after receipt of aggression only occurred if animals were subsequently placed in the restraint chair. A summation of stressful effects is therefore required to produce the fall in circulating LH. A summation of social and other environmental stressors may also underlie the reduced fertility seen in free-living animals.
与攻击性遭遇和低社会等级相关的应激刺激可能会影响多种哺乳动物物种中雌性的生育能力。在这些实验中，我们研究了在灵长类动物座椅上进行攻击性遭遇和身体束缚对卵巢切除、雌激素预处理的雌性狨猴促黄体生成素（LH）分泌模式的影响。接受来自同种雌性的攻击，随后进行身体束缚以采集血样（每隔10分钟采集一次，共4小时），导致五只动物在雌二醇诱导的LH激增期间LH浓度显著下降（从112±24微克/升降至45±12微克/升；组均值±标准误；P<0.05）。这是由于LH脉冲幅度降低而非脉冲频率改变所致。用外源性促性腺激素释放激素（LHRH）治疗雌性可逆转LH血浆浓度的下降。皮质醇治疗对雌激素诱导的LH激增期间的LH水平没有影响。因此，攻击性遭遇和身体束缚对血浆LH的影响并非由于垂体对LHRH的反应性降低或血浆皮质醇浓度升高。在单独的实验中发现，仅身体束缚对习惯化的动物血浆LH没有影响，并且只有在动物随后被放置在束缚椅上时，接受攻击后血浆LH才会下降。因此，需要应激效应的累加才能导致循环LH下降。社会和其他环境应激源的累加也可能是自由生活动物生育能力降低的原因。
