摘要
Ovariectomized ewes were injected with either 10 or 30 mg of progesterone, administered either intramuscularly (im) or subcutaneously (sc) at 24, 8, 4 h before, or at the same time, as im injections of 1, 2 or 4 mg of estradiol-17β. Determinations of serum luteinizing hormone (LH), estrogen, and progesterone by radioimmunoassay (RIA) were conducted to study the effects of the treatments on LH release, and the time course of estrogen and progesterone serum concentrations following injection. In the first experiment, progesterone failed to block the estrogen-induced LH release in four of six ewes, and in all three ewes of the second experiment. Intramuscular injection of progesterone resulted in higher circulating progesterone concentrations than sc injection and reached peak levels at 2–4 h postinjection. Estrogen reached peak values at 30 min–2 h postinjection. The results showed that progesterone injected at either 4, 8 and 24 h before, or simultaneously with, a pharmacological dosage of estrogen did not consistently block the LH release in ovariectomized ewes.
摘要译文
给卵巢切除的母羊注射10或30μmg的孕酮，在注射前，同时，同时24、8、4μh或同时肌肉注射（im）或皮下注射（sc），每次注射1、2或4μmg雌二醇—17β。通过放射免疫法（RIA）测定血清黄体生成素（LH），雌激素和孕酮，以研究该疗法对LH释放的影响，以及注射后雌激素和孕激素的浓度随时间的变化。在第一个实验中，孕酮未能在第二个实验的六头母羊中的四头和所有三头母羊中阻止雌激素诱导的LH释放。肌注黄体酮比sc注射产生更高的循环孕酮浓度，并在注射后2-4h达到峰值。注射后30 min–2 h，雌激素达到峰值。结果表明，在雌激素的药理学剂量之前或同时，4、8、24h注射黄体酮并不能始终如一地阻断去卵巢母羊中LH的释放。
P. YUTHASASTRAKOSOL; ; S. SIMARAKS; ; W. M. PALMER; B. E. HOWLAND. ESTROGEN-INDUCED LH RELEASE IN PROGESTERONE-TREATED OVARIECTOMIZED EWES[J]. Canadian Journal of Animal Science, 1974,54(4): 565-572