Placental transfer and tissue localization of [14C]carmoisine in the pregnant rat.

Pregnant Sprague-Dawley rats received [14C]Carmoisine (200 mg/kg; 25 microCi) by gavage, on days 16-19 of gestation. Animals were killed on day 19 of gestation, 2, 16, 64 h after dosing and blood, maternal tissues, amniotic fluids, placentae, fetal membranes and fetuses were analyzed for radioactivity. No evidence for the transplacental transfer of [14C]Carmoisine or its metabolites was obtained. More than 90% of the radioactivity was excreted in feces and urine within 64 h.