Metabolic Fate of a Novel Antiulcer Agent, T-593 (II): Transfer into Fetus and Milk in Rats

The transfer of radioactivity into the fetus and milk after oral administration of 14C-T-593 at a dose of 10 mg/kg were investigated in pregnant and lactating rats. 1. The levels of radioactivity in the whole fetus and fetal tissues at 2 hr, after oral administration of 14CT-593 at a dose of 10 mg/kg to fasting pregnant rats on 19th day of gestation, accounted for less than 16.8% of that in the maternal plasma. The radioactivity in the fetal tissues was eliminated slowly when compared with the elimination from the maternal tissues. 2. The whole body autoradiograms, after oral administration of 14C-T-593 at a dose of 10 mg/kg to fasting pregnant rats on 12th and 19th day of gestation, showed that radioactivity was scarcely noted in the fetus. 3. The levels of radioactivity in the milk, after oral administration of 14C-T-593 at a dose of 10 mg/kg to non-fasting lactating rats, reached the Cmax at 6 hr and was 2.4 times higher than that in the plasma. The levels in milk decreased in parallel with that in plasma.