The Effect of Constant Infusion of Unlabeled Dehydroepiandrosterone Sulfate on Maternal Plasma Androgens and Estrogens

Abstract

A bolus iv injection of 50 mg dehydroepiandrosterone sulfate (DS) followed by a constant 2-h infusion of 200 εg DS/min was administered to 5 pregnant patients at term and to 5 postpartum patients. Its effect on plasma androgen and estrogen concentrations wasdetermined by frequent plasma hormone determinations. At the end of the constant infusion plasma DS concentrations were 7-fold higher than pre-treatment levels in both postpartum and pregnant patients. The metabolic clearance rates (MCR) of the infused DS for pregnant and postpartum patients were 1.2 and 1.0 liter/kg/day, and the half-lives 146 and 179 min, respectively (P > 0.05). A 3-fold rise of plasma dehydroepiandrosterone concentrations, which was observed in pregnant as well as postpartum patients, suggested that the rise of plasma dehydroepiandrosterone was due to peripheral rather than placental metabolism of DS. The rise of plasma androstenedione and testosterone following DS infusion, which was greater in postpartum than in pregnant patients, also suggested peripheral origin of these androgens. A 2½-fold rise of plasma estradiol (E₂) which was observed at the end of the constant DS infusion concurred with previous observations that 30–40% of maternal circulating E₂ was derived from maternal DS. The lack of rise of plasma estriol following constant DS infusion would suggest that the infused DS competes with endogenous 16-a-hydroxy-DS on the aromatase system.