McNeilly A S, Swanston I A, Crow W, Tsonis C G, Baird D T
MRC Reproductive Biology Unit, Centre for Reproductive Biology, University of Edinburgh.
J Endocrinol. 1989 Feb;120(2):295-305. doi: 10.1677/joe.0.1200295.
A radioimmunoassay for inhibin was developed using a peptide containing the 1-26 amino acid sequence of the N-terminus of the alpha-chain of 32 kDa porcine inhibin as immunogen, and 125I-labelled tracer. Evaluation of this assay using Sephadex column chromatography, chromatoelectrophoresis and immunoblotting confirmed that it measured all forms of inhibin present in sheep follicular fluid and was suitable for measurement of inhibin in sheep plasma. There was no evidence of the presence of free alpha-subunit in either sheep follicular fluid or ovarian vein plasma. The concentration of inhibin in jugular plasma throughout the follicular and luteal phases of four ewes with ovarian autotransplants was measured. The ovarian secretion of inhibin and oestradiol were also measured simultaneously throughout the follicular phase in a spontaneous cycle and after infusion of NIH-oFSH-S14 at 10 micrograms/h for 48 h following premature luteal regression induced by prostaglandin. The results showed: (1) no change in the peripheral concentration of inhibin throughout the cycle except an increase related to the periovulatory increase in FSH and LH. (2) Following luteal regression, the concentration of FSH fell as the secretion rate of oestradiol increased. During this time there was no significant change in the peripheral concentration of inhibin or ovarian inhibin secretion rate. (3) Following the infusion of FSH there was a marked increase in the concentration of inhibin in both ovarian and peripheral plasma and an increase in ovarian inhibin secretion rate. (4) The calculated metabolic clearance rate of inhibin, 20.3 ml/min, is similar to that of FSH. We conclude that in the ewe the ovarian inhibin secretion rate is stimulated by FSH and, although inhibin may modulate the basal secretion of FSH, a change in its secretion does not account for the fall in FSH which occurs during the follicular phase of the sheep oestrous cycle.
利用包含32 kDa猪抑制素α链N端1 - 26个氨基酸序列的肽作为免疫原，以及125I标记的示踪剂，开发了一种抑制素放射免疫分析方法。使用葡聚糖凝胶柱色谱、色谱电泳和免疫印迹对该分析方法进行评估，证实它能检测绵羊卵泡液中存在的所有形式的抑制素，适用于测量绵羊血浆中的抑制素。在绵羊卵泡液或卵巢静脉血浆中均未发现游离α亚基存在的证据。对4只进行卵巢自体移植的母羊在卵泡期和黄体期整个过程中颈静脉血浆中抑制素的浓度进行了测量。在自然周期的卵泡期以及在前列腺素诱导黄体过早退化后以10微克/小时的速度注入NIH - oFSH - S14持续48小时后，同时测量了抑制素和雌二醇的卵巢分泌量。结果显示：（1）在整个周期中，外周血中抑制素浓度无变化，仅在排卵前与促卵泡素（FSH）和促黄体生成素（LH）的增加有关的情况下有所升高。（2）黄体退化后，随着雌二醇分泌率增加，FSH浓度下降。在此期间，外周血中抑制素浓度或卵巢抑制素分泌率无显著变化。（3）注入FSH后，卵巢和外周血浆中抑制素浓度显著升高，卵巢抑制素分泌率增加。（4）计算得出的抑制素代谢清除率为20.3毫升/分钟，与FSH相似。我们得出结论，在母羊中，FSH刺激卵巢抑制素分泌率，尽管抑制素可能调节FSH的基础分泌，但在绵羊发情周期的卵泡期，其分泌变化并不能解释FSH的下降。
