Renal microsomal N-nitrosodimethylamine demethylase determined by a sensitive radiometric method.
Renal microsomal N-nitrosodimethylamine (NDMA) N-demethylation was measured in several species by a sensitive radiometric method using [14C]NDMA as a substrate and 2,4-dinitrophenylhydrazine (DNPH) as a trapping agent of the [14C]formaldehyde formed. The activities were the highest in mice and lowest in hamsters. The activities in rats could not be detected. Among several strains of mice studied the DDY strain was the highest in its activities. Although nicotinamide adenine dinucleotide supported NDMA demethylation by about 32% of nicotinamide adenine dinucleotide phosphate in kidney and only 16% in liver, other properties (pH profiles, km values, and effects of inhibitors) exhibited almost similar results in liver as compared to kidney.
D000818:Animals; D002250:Carbon Radioisotopes; D002855:Chromatography, Thin Layer; D006224:Cricetinae; D019392:Cytochrome P-450 CYP2E1; D005557:Formaldehyde / Q000096:biosynthesis; D066298:In Vitro Techniques; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008297:Male; D008647:Mesocricetus; D008745:Methylation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008861:Microsomes / Q000201:enzymology*; D010089:Oxidoreductases, N-Demethylating / Q000032:analysis* / Q000494:pharmacology; D010659:Phenylhydrazines; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity
D002250:Carbon Radioisotopes; D010659:Phenylhydrazines; D005557:Formaldehyde; C004787:2,4-dinitrophenylhydrazine; D019392:Cytochrome P-450 CYP2E1; D010089:Oxidoreductases, N-Demethylating