Metabolic Fate of a Benzoylphenylurea Derivative, Ho-221. (III). Transfer into Fetus, Milk and Tumor.

Abstract

The transfer into fetus, milk and tumor of a benzoylphenylurea derivative, HO-221 was studied after oral administration of 14C(Pc) HO-221 to rats at a dose of 25 mg/kg. The radioactivity levels in the fetuses on the 12th and 18th days of gestation were 35 and 67% of those in the maternal plasma, respectively. The radioactivity level in the fetus on the 12th day of gestation was below the detection limit at 48 hr after administration. The radioactivity levels in the fetal tissues, except the intestinal contents, on the 18th day of gestation were less than 14% of the maximum. The radioactivity level in the milk was 3-4 times higher than that in the plasma up to 12 hr after administration. The elimination of radioactivity from the milk was more rapid than from the plasma. The radioactivity level in the tumor was similar to that in the plasma. No difference was noted in the distribution of radioactivity into the tissues and the excretion of radioactivity in the urine and feces between tumor bearing and normal male rats.