[Immunomorphological study of cytochrome P-450PB induction in the liver of rat embryos and pregnant females after phenobarbital administration].

Cytochrome P-450 PB localization in the livers of embryos, pregnant, non-pregnant female, and male Wistar rats was investigated immunomorphologically after phenobarbital (PB) treatment. The highest level of cytochrome P-450 PB induction was observed in the livers of male rats where the antigen invaded almost the whole liver lobule. About half of the cells within the lobule of non-pregnant female rat livers were stained and were located around the central vein area. Pregnant females had two times less indication than the non-pregnant group and only a quarter of the cells in the lobule of the liver adjacent to the central vein were stained for P-450 PB. The indication of cytochrome P-450 PB was absent from 17-18-day-old embryonal livers which were subjected to the transplacental action of the inducer. Only in one case out of seven were small groups of cells and single cells in the embryonal liver stained positively for cytochrome P-450 PB. It is obvious that during pregnancy, the mother's body exerts a significant influence on the detoxifying function of the fetal liver.