Bioalkylation of nucleic acids in mice by insecticides. I. Alkylation of liver RNA and DNA by chlorpyrifos.
Male mice were i.p. injected with two doses (5 & 15 mg/kg body weight) of [1-14C]ethyl-labelled chlorpyrifos. The radioactivity in liver, fat, kidney and urine was measured 6, 24, 48, and 192 h after treatment. Liver RNA and DNA were isolated and hydrolyzed and the bases separated by ion-exchange chromatography. Radioactivity resulting from incorporation and alkylation of RNA and DNA was measured. Labelled 7-ethylguanine was found in RNA hydrolysate which amounted 5.5 X 10(-3) calculated as fraction of the applied dose. In DNA hydrolysate [14C]7-ethylguanine was missing and the major radioactivity was found in two unknown peaks, one of which corresponds to 3 X 10(-2) of the applied dose. The results indicate that the extent of alkylation obtained with chlorpyrifos is high as compared with other organophosphates with methyl esters.
D000478:Alkylation; D000818:Animals; D002250:Carbon Radioisotopes; D004390:Chlorpyrifos / Q000378:metabolism / Q000633:toxicity*; D004247:DNA / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051379:Mice; D012313:RNA / Q000378:metabolism*
D002250:Carbon Radioisotopes; D012313:RNA; D004247:DNA; D004390:Chlorpyrifos