Environment and hamster reproduction: responses to phase-specific starvation during estrous cycle.
Environment and hamster reproduction: responses to phase-specific starvation during estrous cycle.
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环境和仓鼠繁殖：对发情周期期间特定阶段饥饿的反应。
DOI：
10.1152/ajpregu.1986.251.4.r663
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Morin,LP
中科院分区：
文献类型：
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作者：
Morin,LP
根据排卵反应估计，雌性仓鼠的繁殖能力特别容易受到食物剥夺的干扰。此前的研究表明，仓鼠如果被剥夺一到两个发情周期的食物，通常不会排卵。目前的工作表明，仅在排卵后2天内发生的饥饿会阻碍大约80%的动物下一次预期的排卵。这种阶段性饥饿还导致卵巢卵泡明显变小。当无排卵动物与强壮的雄性动物放在一起时，除非提供外源苯甲酸雌二醇酯(EB)，否则不能表现出前凸行为。在提供EB的情况下，所有动物都表现出短潜伏期前凸。这些生物测定数据表明，发育不良的卵泡分泌的雌二醇不足，不足以促进前凸。周期第4天关灯前6h注射外源黄体生成素(L H)不能诱导排卵，进一步提示卵泡未成熟。放射免疫分析显示，在排卵期促性腺激素高峰期间，促黄体生成素和卵泡刺激素(FSH)水平显著降低，而FSH处于低至正常范围。与对照组相比，在促性腺激素激增之前立即测定的雌二醇水平较低，而孕酮水平高于正常水平。结果表明，阶段性食物缺乏所致的排卵失败是缺乏排卵性黄体生成素高峰和一组未成熟卵泡共同作用的结果。
Reproductive capacity of female hamsters, as estimated by the ovulatory response, is particularly susceptible to interference by food deprivation. Previous studies showed that hamsters generally fail to ovulate if deprived of food for one or two estrous cycles. The present work demonstrates that starvation which is specific to the 2 days immediately after ovulation will block the next expected ovulation in approximately 80% of the animals. Such phasic starvation also resulted in significantly smaller ovarian follicle sizes. When placed with vigorous males, anovulatory animals failed to show lordosis behavior unless exogenous estradiol benzoate (EB) was supplied. With EB provided, all animals showed short-latency lordosis. These bioassay data suggested that poorly developed follicles were secreting insufficient estradiol for the facilitation of lordosis. Exogenous luteinizing hormone (LH) given 6 h before lights off on cycle day 4 failed to elicit ovulation, further suggesting that the follicles were not mature. Radioimmunoassay of LH and follicle-stimulating hormone (FSH) levels during the ovulatory gonadotropin surge showed that LH was vastly reduced, whereas FSH was in the low-to-normal range. Estradiol levels, assayed immediately before the gonadotropin surge, were low compared with controls, whereas progesterone levels were higher than normal. The results suggest that ovulatory failure in response to phasic food deprivation is a joint function of absence of an ovulatory LH surge and a set of immature follicles.