DNA methylation in rat liver by daminozide, 1,1-dimethylhydrazine, and dimethylnitrosamine

DNA methylation in rat liver by daminozide, 1,1-dimethylhydrazine, and dimethylnitrosamine.

[methyl-14C]Daminozide (succinic acid 2',2'-dimethylhydrazide; 37 mg/kg), 1,1-[14C]dimethylhydrazine (UDMH; 19 mg/kg), and [14C]dimethylnitrosamine (DMNA; 0.1 mg/kg) were administered by oral gavage to male Sprague-Dawley rats. After 24 hr, the animals were killed and DNA was purified from the livers to constant specific radioactivity. After enzymatic degradation of the DNA to the 3'-deoxynucle...

Toxic liver injury and carcinogenesis. Methylation of proteins of rat-liver slices by dimethylnitrosamine in vitro.

Methylation of nuclear proteins by dimethylnitrosamine and by methionine in the rat in vivo.

1. The incorporation of methyl groups into histones from dimethylnitrosamine and from methionine was studied by injection of the labelled compounds, isolation of rat liver and kidney histones, and analysis of hydrolysates by column chromatography. 2. Labelled methionine gave rise to labelled in-N-methyl-lysine, di-in-N-methyl-lysine and an amino acid presumed to be omega-N-methyl-arginine. 3. A...

Metabolism of dimethylnitrosamine and 1,2-dimethylhydrazine in cultured human bronchi.

The metabolic activation of several chemical classes of procarcinogens is being studied in cultured human bronchi. Previous studies have shown that carcinogenic polynuclear aromatic hydrocarbons are metabolically activated by the bronchial epithelium. In the study reported here, dimethylnitrosamine and 1,2-dimethylhydrazine were also found to bind to both cellular DNA and protein. Bronchial DNA...

Dose-dependent DNA ruptures induced by the procarcinogen dimethylnitrosamine on primary rat liver cultures.

The effect of certain procarcinogens, among which demethylnitrosamine (DMN) is included, has been difficult to detect in several short-term assays. An alternative system, in which DMN effects could be easily quantitated, might be useful in studies of chemical carcinogenesis and environmental contamination. To develop such a system, we tested the possibility of measuring the amount of breakage p...