Dimethylnitrosamine adducts excreted in rat urine |
| |
Authors: | Kari Hemminki |
| |
Affiliation: | Department of Industrial Hygiene and Toxicology, Institute of Occupational Health, Haartmaninkatu 1, SF-00290 Helsinki 29 Finland |
| |
Abstract: | Rats were injected with [14C] dimethylnitrosamine and urine was collected up to 5 days after the injection. Urine samples were concentrated and subjected to Sephadex G-10 chromatography. Three peaks of radioactivity (I–III, in the order of elution) were observed for all injection times. The peaks were analysed further by cation exchange and thin-layer chromatography and by phase-separation (pH-determination). The pK-determinations and the chromatographic properties suggested that Sephadex fraction I composed of methylated amino acids, such as N-acetyl-S-methylcysteine, 1-methylhistamine and S-methylcysteine, in addition to radioactive methionine. Sephadex fraction II was suggested to compose of allantoin and of a metabolite of thiazolidine-4-carboxylic acid. The latter compound was a reaction product of formaldehyde and cysteine, indicating activity of the formaldehyde moiety released from dimethylnitrosamine. By gel filtration properties Sephadex fraction III indicated identity as 7-methylguanine. Altogether the urinary radioactivity accounted for about 9% of the applied dose. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|