Altered secretion of gonadotropins and steroids resulting from delayed ovulation in the rat.
Altered secretion of gonadotropins and steroids resulting from delayed ovulation in the rat.
复制标题
大鼠排卵延迟导致促性腺激素和类固醇分泌改变。
DOI：
10.1210/endo-96-3-576
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发表时间：
1975
期刊：
影响因子：
4.8
通讯作者：
N. W. Fugo
中科院分区：
文献类型：
--
作者：
R. Butcher;W. E. Collins;N. W. Fugo
在戊巴比妥钠诱导的排卵延迟48h期间，以及随后的发情前期、发情期和妊娠前4天，每隔3小时断头处死大鼠。对照组动物在注射车辆后以相同的时间间隔被处死。采集血液并分析促黄体生成素、卵泡刺激素、催乳素、孕酮和雌二醇-17β，以确定激素水平的变化是否可以解释排卵延迟后胚胎发育的异常。用放射免疫法测定血浆中的激素浓度，用竞争性蛋白结合法测定孕酮。对胚胎进行检查，以证实是否发生了异常发育。对发情前期下午每隔30分钟处死动物的卵巢连续切片的卵母细胞成熟率进行了研究。在48h的延迟排卵过程中，卵母细胞仍然处于减数分裂停滞状态，但在排卵前促性腺激素激增的下午，卵母细胞恢复了预期的成熟。在延迟排卵后，受精卵退化(6.5vs1.9%)、发育异常(3.7vs0.7%)和发育迟缓(3.1vs0.2%)的比例显著增加。在长时间的排卵前期，激素水平发生了许多变化。用Nembutal治疗两天后，血浆中促黄体生成素的发情高峰被完全抑制，但在第二天出现正常的排卵前高峰。FSH在治疗的两天都有轻微但显著的上升。治疗后第2天FSH峰值与正常排卵前峰值无明显差异，但峰值持续时间缩短12h，治疗后第2天血浆催乳素和孕酮水平仅受到部分抑制，排卵前催乳素水平显著高于对照组。雌二醇的发情高峰出现在第一次注射Nembutal之前，在注射Nembutal后逐渐下降。在延迟排卵期间，血浆雌二醇水平一直高于基础水平，在第二次治疗当天和排卵前一天的15u0h出现较短的峰值。妊娠前4天血浆这5种激素水平不受排卵延迟的影响。
Rats were killed by decapitation at 3-h intervals during a 48-h delay of ovulation induced by sodium pentobarbital, as well as during the ensuing delayed proestrus, estrus and the first 4 days of gestation. Control animals were killed at the same intervals following injections of vehicle. Blood was collected and analyzed for LH, FSH, prolactin, progesterone and estradiol-17beta to determine if alterations in hormonal levels could account for the abnormal embryonic development which follows delayed ovulation. Hormonal concentrations in plasma were measured by radioimmunoassay except for progesterone, which was determined by competitive protein binding. Embryos were examined to verify the occurrence of abnormal development. Rate of oocyte maturation was studied in serial sections of ovaries from all animals killed at 30-min intervals on the afternoon of proestrus. Oocytes remained in meiotic arrest during the 48-h delay of ovulation, but resumed maturation at the expected time on the afternoon of the preovulatory surge of gonadotropins. Following delayed ovulation there was a significant increase in fertilized ova that were undergoing degeneration (6.5 vs 1.9%), abnormal development (3.7 vs 0.7%), and retarded development (3.1 vs 0.2%). A number of alterations in hormonal levels occurred during the prolonged preovulatory period. The proestrous surge of LH in plasma was completely suppressed on both days of treatment with Nembutal, but exhibited a normal preovulatory peak on the following day. FSH showed a small but significant rise on both days of treatment. Peak concentrations of FSH on the following day were not different in magnitude from the normal preovulatory surge, although the duration of this surge was shortened by 12 h. Prolactin and progesterone concentrations in plasma were only partially suppressed on the days of treatment, while on the following day preovulatory levels of prolactin were significantly greater than in controls. The proestrous peak levels of estradiol occurred prior to the first Nembutal injection and declined more gradually after this treatment. Plasma levels of estradiol remained above basal levels during the period of delayed ovulation with peaks of short duration at 15u0 h on the day of second treatment and the day prior to ovulation. Plasma levels of these 5 hormones during the first 4 days of gestation were not altered by delayed ovulation.