The metabolism of isolated rat-liver nuclei during chemical carcinogenesis. Thioacetamide and p-dimethylaminoazobenzene (butter yellow)

Abstract

Nuclei were isolated in 0.25 [image]-sucrose from the livers of normal rats and of rats fed with either thioacetamide or p-dimethyl-aminoazobenzene. Nuclear counts, nuclear nitrogen, DNA, RNA, and phospholipids were determined on the nuclei of treated rats at intervals during the 22-week feeding period. In all cases an increase over controls was obtained during the early weeks of feeding. The incorporation in vitro of [2-14c]glycine into protein, and [6-14C]orotic acid and [8-14c]-adenine into RNA of the isolated nuclei was studied in control and treated animals over the feeding period. Orotic acid and adenine incorporation fell in thioacetamide-treated animals and rose in p-di-methylaminoazobenzene treatment. The results are correlated with the histology of the livers of the treated rats and discussed in relation to carcinogenesis.