Cocaine's effect on plasma oxytocin concentrations in the baboon during late pregnancy.

Abstract

The hypothesis for this investigation was that intravenous cocaine would result in an elevation of maternal plasma oxytocin levels in the baboon during late pregnancy. Five gravid chronically instrumented baboons had timed arterial blood samples obtained before and after an intravenous bolus cocaine infusion at least 5 days after surgery. Plasma oxytocin concentrations were measured by specific radioimmunoassays, and baseline samples were compared with postcocaine samples. The plasma oxytocin concentrations were significantly elevated at all sampling times after the 1.0 mg/kg cocaine dose (p<0.05). The increased oxytocin concentration after cocaine use may be responsible for the increased incidence of preterm labor.