Nacroautoradiographic assays in pregnant mice and their fetuses given N-acetyl-9-[14C]-2-aminofluorene and p-[14C]-dimethylaminoazobenzene.

The distribution of radioactivity from N-acetyl-9-[114C]-2-aminofluorene and p-[14C]-dimethylaminoazobenzene administered i.v. or p.o. to 18-day-pregnant mice was observed by means of autoradiography of longitudinal section of the whole mouse. Radioactive substances derived from these carcinogens passed through the placenta and were distributed in the fetal organs including the kidney and intestine. Column, thin-layer, and paper chromatography revealed the presence, in while fetuses as well as in maternal livers, of N-acety-9-[14C]-2-aminofluorene. N-hydroxy-N-acetyl-9-[14C]-2-aminofluorene, ring-hydroxy-N-acetyl-9-[14C]-2-aminofluorene, and p-[14C]-dimethylaminoazobenzene. These results establish that N-acetyl-9-[14C]-2-aminofluorene and [14C]-p-dimethylaminoazobenzene are transported, metabolized, and excreted in the mouse fetus.