Metabolic Fate of a New Dihydropyridine Calcium Antagonist, AE0047 (III): Placental Transfer and Milk Transfer of 14C-AE0047

The transfer of radioactivity to fetus and milk were studied in the pregnant or lactating rats after a single oral administration of 14C-AE0047 at the dose of 3 mg/kg. The localization of the radioactivity was visualized by whole body autoradioluminography and was determined by the excised tissue-liquid scintillation method. 1. When 14C-AE0047 was administered orally at a dose of 3 mg/kg to pregnant rats (19th day of gestation), the maximum levels of radioactivity in the fetus were observed at 6 hr after the administration and accounted for 6.0% of the Cmax present in the maternal plasma. The amounts of radioactivity transferred to one fetus was 0.009 to 0.015% of administered dose. 2. When 14C-AE0047 was administered orally at a dose of 3 mg/kg to lactating rats (the 19th day after delivery), the maximum level in milk was reached at 6 hr and it was lower than that in the maternal plasma.