[Sex steroids in the initiation of puberty genesis in female rats].

In the female rats it has been estimated the initial (vaginal opening) and final (the establishment of the positive feedback and ovulation) stages of the sexual maturation are in most cases separated by time and regulated by different testosterone metabolites. The considerable decrease of testosterone and its biotransformation to 5 alpha-reduced androgens are necessary for induction of initial puberty stage. Duration between the beginning and the ending of the pubertogenesis depends on the way of the testosterone metabolism. The transformation of testosterone to 5 alpha-reduced androgen stimulates the vaginal opening, but enlarges the time of the first ovulation. The activation of testosterone aromatization promotes to the shortening of the time interval or even the temporal coincidence of the initial and final puberty stages.