INTRAUTERINE EXPOSURE TO COCAINE INCREASED PLASMA ANP (ATRIAL-NATRIURETIC-PEPTIDE) BUT DID NOT ALTER HYPOXANTHINE CONCENTRATIONS IN THE SHEEP FETUS

To assess the effects of cocaine, administered to the ewe, on the secr etion of atrial natriuretic peptide (ANP), Plasma Renin Activity (PRA) and hypoxanthine in the fetus we studied 6 chronically cannulated she ep fetuses late in gestation. The ewe was given an intravenous injecti on of cocaine (2 mg/kg). Maternal and fetal arterial blood samples wer e withdrawn prior to the injection and at 2, 5, 10, 15, 45 and 60 min after the injection for the measurement of ANP, PRA and hypoxanthine. Fetal arterial blood pressure (MAP), plasma ANP and protein levels inc reased and pH and pO(2) decreased after cocaine was administered to th e ewe. Fetal plasma hypoxanthine and PRA did not change. These results suggest that cocaine administration to the ewe is associated with fet al hypertension, hypoxemia and acidemia all of which may serve as stim uli for the secretion of ANP.