Androstenedione

Androstenedione (4-Androstene-3, 17-dione), a 19 carbon steroid, is produced in the adrenal gland and gonads. It is an immediate precursor to both testosterone and estrone, both of which may be subsequently converted to estradiol. Androstenedione is a weak androgen and its physiologic role is not well defined. Serum androstenedione levels are high in fetus and neonates, decrease during childhood and increase at puberty. In normal pubertal and adult male, the major portion of androstenedione derives from the testis, either directly or from conversion of testosterone, while in pubertal and adult female, androstenedione is essentially produced by the adrenal gland and ovary. Androstenedione may play a role in the development of secondary sexual hair during adrenarche. Adrenal androstenedione production gradually declines with advanced age in both male and female. Ovarian androstenedione production is stimulated by luteinizing hormone and varies with the menstrual cycle and decreases after menopause.