Prevention by Progesterone of Steroid-Induced Sterility in Neonatal Male and Female Rats

Abstract

Five-day-old female rats injected with 50 or 100 [mu]g of testosterone propionate had, at 45 days of age, ovaries containing only follicles. When 3000 [mu]g of progesterone was injected at the same time all the rats ovulated. Progesterone also protected 5-day-old male animals against the sterilizing effect of ethynyl estradiol 3-methyl ether. On the basis of these results, it is suggested that hypogonadal syndromes may result from low progesterone levels during pregnancy which fail to protect the hypothalamic-hypophysial-gonadal axis.