Ganjam V K, Kenney R M, Flickinger G
J Reprod Fertil Suppl. 1975 Oct(23):183-8.
The disappearance rate of progesterone from blood plasma of an ovariectomized mare was rapid and occurred in three phases. The half-life of the first component was 2-5 min and that of the second was 20 min; the half-life of the much slower third component was not measured. Progesterone, administered to ovariectomized and deeply anoestrous mares at the rate of 150 or 300 mg/day, maintained maximal peripheral levels of 6 to 8 ng/ml. Physiological levels were reached in 21 days using a dose of 150 mg and in 11 days with 300 mg daily. After withdrawal, circulating levels dropped rapidly. Blood plasma of mares appears to lack progesterone-specific binding proteins. It is concluded that the problem of habitual abortion and its treatment in mares need re-evaluation.
去势母马血浆中孕酮的消失速度很快，分为三个阶段。第一成分的半衰期为2 - 5分钟，第二成分的半衰期为20分钟；未测定慢得多的第三成分的半衰期。以150或300毫克/天的剂量给去势且处于深度发情间期的母马注射孕酮，可维持外周血中6至8纳克/毫升的最大水平。使用150毫克剂量时，21天达到生理水平；每日300毫克时，11天达到生理水平。停药后，循环水平迅速下降。母马血浆似乎缺乏孕酮特异性结合蛋白。结论是，母马习惯性流产及其治疗问题需要重新评估。
