Tsonis C G, McNeilly A S, Baird D T
Department of Obstetrics and Gynaecology, University of Edinburgh.
J Endocrinol. 1988 May;117(2):283-91. doi: 10.1677/joe.0.1170283.
The secretion of oestradiol and inhibin were measured during the follicular and luteal phase of the cycle by a sensitive bioassay using sheep pituitary cells in culture in four ewes in which the left ovary had been autotransplanted to the neck. On day 12 of the cycle, premature luteal regression was induced with an injection of 100 micrograms cloprostenol (prostaglandin F2 alpha analogue; PG) and ovarian venous blood was collected every 4 h for 72 h. These same four ewes were infused in the ensuing cycle with NIH-oFSH-S14 at 10 micrograms/h for 48 h immediately after an injection of PG and sampled as above. During the luteal phase (-2 h before PG) both in the control and FSH-infused cycles the inhibin secretion rate (SR) was 27-45 units/min. After PG injection, the inhibin SR declined with time to reach 3.6-5 units/min at the onset of the LH surge (60 h after PG) in the control cycle. In contrast, in the following cycle infusion of FSH after PG injection caused a slight increase in the inhibin SR which then remained raised at 42-50 units/min for up to 60 h after PG. In the late follicular phase the oestradiol SR was greater in the FSH-infused than in the control cycles, indicating multiple follicular development. In the FSH-infused cycle the preovulatory surges of LH and FSH were markedly attenuated. These data demonstrate that (1) inhibin SR is high during the luteal phase suggesting that the sheep corpus luteum secretes inhibin, (2) in the control cycle inhibin SR declines during follicular maturation at a time when oestradiol SR is increasing but FSH levels are decreasing, and (3) exogenously administered FSH stimulates the secretion of inhibin from the ovary during the follicular phase.
通过一种灵敏的生物测定法，在四个左卵巢已自体移植到颈部的母羊的卵泡期和黄体期，测量雌二醇和抑制素的分泌，该生物测定法使用培养的绵羊垂体细胞。在周期的第12天，注射100微克氯前列醇（前列腺素F2α类似物；PG）诱导黄体过早退化，并在72小时内每4小时采集一次卵巢静脉血。在随后的周期中，这四只相同的母羊在注射PG后立即以10微克/小时的速度输注NIH-oFSH-S14，持续48小时，并按上述方法取样。在黄体期（PG前-2小时），在对照周期和FSH输注周期中抑制素分泌率（SR）均为27 - 45单位/分钟。注射PG后，对照周期中抑制素SR随时间下降，在LH峰开始时（PG后60小时）降至3.6 - 5单位/分钟。相比之下，在随后的周期中，PG注射后输注FSH导致抑制素SR略有增加，然后在PG后长达60小时内保持在42 - 50单位/分钟。在卵泡晚期，FSH输注周期中的雌二醇SR高于对照周期，表明有多个卵泡发育。在FSH输注周期中，LH和FSH的排卵前峰明显减弱。这些数据表明：（1）黄体期抑制素SR较高，提示绵羊黄体分泌抑制素；（2）在对照周期中，卵泡成熟期间抑制素SR下降，此时雌二醇SR增加但FSH水平下降；（3）在卵泡期，外源性给予的FSH刺激卵巢分泌抑制素。
