On the Mechanism of the Onset of Puberty: Identification and Pattern of 5α-Androstane-3β,17β-diol and Its 3α Epimer in Peripheral Blood of Immature Female Rats
The steroids 5α-androstane-3α,17βdiol (3α) and its 3β epimer (3β) have been identified in peripheral circulation of immature female rats. Identification of these compounds is based on gas-liquid chromatography, derivative formation and on recrystallization of the diacetates prepared with tritiated acetic anhydride to constant specific activity. Induction of precocious puberty in the female rat by sc administration of 3β(100 μg/day), could be achieved only when the injections were started not later than the 25th day of life and only until this day could 3β be detected in the peripheral circulation. Epimer ratio (3α/3β was found to change from unity on days 22 and 23, up to 2.4 on the 26th day of life. When the two epimers were administered simultaneously in ratios similar to those found normally, the 3α did not interfere with the action of 3β in advancing sexual maturation. A dose of 25 μg 3β injected from the 21st to the 25th, day of life seems to be the minimal dose required to induce precocious puberty. A calculation based on the concentration of 3β found in the blood and the regression line of a dose response curve of the effect of 3β shows that the concentration of 3β found in the blood is sufficient to account for the induction of the onset of puberty at the time when it normally occurs. (Endocrinology94: 224, 1974)