雌性鸭胚胎和雏鸭的抑制素和促性腺激素的分泌

测定了从孵化 ２１ ｄ 到出壳后 １ 日龄雌性鸭胚胎和初生雏 鸭外周及卵巢中具免疫活性的抑制素含量，同时也测定了促卵泡生成素（ Ｆ Ｓ Ｈ）和促黄体生成素（ Ｌ Ｈ）的含量⒚在判定有效后，用牛的抑制素放射免疫系统测定抑制素的含量⒚在第 ２１ 日至 ２５ 日时胚胎血浆中抑制素含量处于低水平， 到第 ２６ 日达到最大值，第 ２７ 日稍降后，抑制素含量在出生后快速下降⒚ Ｆ Ｓ Ｈ 含量在胚胎期无显著变化，其含量的变化与外周抑制素含量的变化相对独立⒚卵巢中抑制素含量在孵 化的第 ２５ 日有显著下降，并于第 ２６ 日时快速回升⒚卵巢和血浆中 抑制素的含量在整个研究阶段后者比前者高约 １０ 倍 ⒚血浆 Ｌ Ｈ 从第 ２１ 日开始下降，至第 ２５ 日 接着有所回升并于第 ２７ 日达第二峰值⒚总之，血浆抑制素和 Ｆ Ｓ Ｈ 在雌性鸭胚胎中不存在负反馈关系， 这预示着胚胎期抑 制素的主要作用 不是抑制垂体分 泌 Ｆ Ｓ Ｈ，同 样 Ｆ Ｓ Ｈ 也不影响抑 制素的分泌⒚

Secretion of inhibin and gonadotropin in female embryos and newly hatched ducks

Concentrations of immunoreactive ( ir) inhibin in circulation and ovary of embryonic and newlyhatched period from 21 d of incubation to 1 d of age were determined. Plasma concentrations of follicle stimulating hormone (FSH) and Luteinizing hormone (LH) were also determined. Ir inhibin was measured by using the bovine radioimmunoassay (RIA) system validated for RIA of inhibin in the duck. Plasma ir inhibin remained low from Day 21 to Day 25, thereafter, significantly increased and reached a maximum value on Day 26. After a small decrease on Day 27, inhibin levels rapidly dropped. No significant changes was observed in plasma FSH in embryonic life. The change in plasma FSH was independent from circulating ir inhibin. A precipitate decline in ovarian ir inhibin was observed at Day 25 and the levels was quickly returned at Day 26. To compare ovarian inhibin and plasma ir inhibin over the period studied, the latter has relatively high levels and was approximately 10 fold higher than the former. Plasma LH decreased from Day 21 to Day 25, thereafter, followed an increase and reached the second peak at Day 27. In conclusion, no obvious inverse relationship was observed between plasma ir inhibin and FSH, suggesting that inhibin does not play a major role in the feedback regulation of pituitary FSH secretion during embryo development.