[Pharmacologic stimulation in delayed female sexual development (response of androstenedione vs. 17 beta-estradiol). Presentation of 2 cases]. / Estímulo farmacológico en el desarrollo sexual femenino retrasado (respuesta de androstendiona vs. 17 beta-estradiol). Presentación de dos casos.

Two girls of 13 and 18 years of age, XX chromosomic pattern, complaining of delay in sexual development (Stage 1) and primary amenorrhea, were studied. Height, weight and surface area in the 13 years subject were three standard deviations below the anthropometric characteristics of already menstruating girls of the same age. Presence of uterus and ovarian tissue was demonstrated by laparoscopy in both, and afterwards, simultaneous measurements of androstenedione (delta 4) and 17 beta-estradiol (E2) were performed in peripheral blood, before and after: placebo, clomiphene (25 and 50 mg), LH-RH, FSH/LH. Under this trials the gonadal structures produced delta 4 and E2, being the former in many instances a good index of ovarian steroid production and associated to growth of pubic and axillary hair. In the patient whose menstruation began after the pharmacologic stimuli, the steroid production was higher as compared to the one, with initiation of no menstrual bleeding. Critical aspects of the various phases of the study are revised to better understand the physiology of some biological processes.