Campbell B K, Mann G E, McNeilly A S, Baird D T
Department of Obstetrics and Gynecology, University of Edinburgh, United Kingdom.
Endocrinology. 1990 Jul;127(1):227-35. doi: 10.1210/endo-127-1-227.
An experiment was conducted in order to determine the pattern of, and the relationships between, the secretion of inhibin, estradiol, and androstenedione by the ovary and the concentration of LH, FSH, and PRL during the estrous cycle of sheep. The estrous cycles of 6 Finn-Merino ewes in which the left ovary had been autotransplanted to the neck were synchronized by two injections of cloprostenol (100 micrograms im) a potent analog of prostaglandin F2 alpha (PG) given 14 days apart. The ewes had ovarian and jugular venous blood samples taken at four hourly intervals from 42 h before the second PG injection until day 6 of the following cycle. All animals responded to PG with the preovulatory LH surge occurring within 58 +/- 2 h (mean +/- SEM). The concentration of FSH in jugular venous plasma fell (P less than 0.001) after the induction of luteolysis and then exhibited 3 peaks, the first coincident with the LH surge, the second on day 1, and the third on day 6. After injection of PG the secretion rates of inhibin, estradiol, and androstenedione increased (P less than 0.05) within 4-8 h. After this increase in the early follicular phase the secretion rate of estradiol continued to rise until the time of the LH surge (P less than 0.001). Although the secretion of androstenedione and inhibin increased in the 36 h before the LH surge the magnitude of this rise was less marked than for estradiol and was not statistically significant. Within 4-8 h of the start of the LH surge the secretion of estradiol and androstenedione declined rapidly reaching barely detectable levels within 16 h (P less than 0.001). In contrast the secretion of inhibin increased after the LH surge reaching a broad peak (P less than 0.05) of approximately 16-h duration, coincident with the second peak of FSH. From days 2-6 mean secretion of inhibin remained relatively stable at 2-6 ng/min although considerable variation was observed in individual profiles. The rate of estradiol secretion increased steadily from its nadir on day 1 to a broad peak centered around day 3 (3-6 ng/min, P less than 0.001) followed by a decline until by day 6 the estradiol secretion rate was less than 1 ng/min (P less than 0.01). The secretory profile for PRL showed a close relationship with estradiol secretion.(ABSTRACT TRUNCATED AT 400 WORDS)
为了确定绵羊发情周期中卵巢分泌抑制素、雌二醇和雄烯二酮的模式及其与促黄体生成素（LH）、促卵泡素（FSH）和催乳素（PRL）浓度之间的关系，进行了一项实验。6只芬兰-美利奴母羊的左卵巢已自体移植至颈部，通过间隔14天两次注射氯前列醇（100微克，肌肉注射）来同步发情周期，氯前列醇是前列腺素F2α（PG）的一种强效类似物。从第二次PG注射前42小时至下一个周期的第6天，每隔4小时采集母羊的卵巢和颈静脉血样。所有动物对PG均有反应，排卵前LH峰在58±2小时内出现（平均值±标准误）。黄体溶解诱导后，颈静脉血浆中FSH浓度下降（P<0.001），然后出现3个峰值，第一个与LH峰同时出现，第二个在第1天，第三个在第6天。注射PG后，抑制素、雌二醇和雄烯二酮的分泌率在4-8小时内增加（P<0.05）。在卵泡早期这种增加之后，雌二醇的分泌率持续上升直至LH峰出现时（P<0.001）。尽管在LH峰前36小时雄烯二酮和抑制素的分泌增加，但其增加幅度不如雌二醇明显，且无统计学意义。在LH峰开始后的4-8小时内，雌二醇和雄烯二酮的分泌迅速下降，在16小时内降至几乎检测不到的水平（P<0.001）。相比之下，抑制素的分泌在LH峰后增加，达到一个持续约16小时的宽峰（P<0.05），与FSH的第二个峰值同时出现。从第2天到第6天，抑制素的平均分泌相对稳定在2-6纳克/分钟，尽管个体曲线存在相当大的差异。雌二醇的分泌率从第1天的最低点稳步上升至以第3天为中心的宽峰（3-6纳克/分钟，P<0.001），随后下降，到第6天时雌二醇分泌率低于1纳克/分钟（P<0.01）。PRL的分泌模式与雌二醇的分泌密切相关。（摘要截断于400字）
