[Synthesis of nucleic RNA in hydroxythiamine-induced vitamin B1 deficiency]

24 hours after administration of hydroxythiamine (vitamin B1 antimetabolite) in a dose of 40 mg per 100 g of body weight, the incorporation of (2(14)C)-orotic acid and (methyl-14C)-methionine into total nuclear RNA decreases. The content of RNA and the specific radioactivity of cytoplasmic UTP and methionine pools remain unchanged. Thermal phenol fractionation of nuclear RNA reveals a decrease in a predominant synthesis of nucleolar RNA, while that of heterogeneous nuclear RNA, tRNA, and 5S-RNA remains unaffected.