Acute dose dependent inhibition of liver nuclear RNA synthesis and methylation of guanine following oral administration of sodium nitrite and dimethylamine to mice

Abstract

Combined oral administration of dimethylamine and sodium nitrite to mice yielded a marked dose dependent inhibition of liver nuclear RNA synthesis. Inhibition of nuclear RNA synthesis was still significant when sodium nitrite was administered 1 h subsequent to dimethylamine; no inhibition of nuclear RNA synthesis was observed when sodium nitrite was given 30 min prior to the dimethylamine. Furthermore, radioactivity was observed in 7‐methyl guanine in liver RNA from mice treated with dimethylamine‐C14 and sodium nitrite but not with di‐methylamine‐C14 alone. This study is of import because of the in vivobiosynthesis of carcinogenic nitrosamines in man following suggestion of nitrites and secondary amines present in food.