Methylation of guanine in vivo by the organophosphorus insecticide methamidophos

Abstract

The methylating capability of m etham idophos, assayed by the formation of [7- 14 C]methylguanine in mouse liver, was investigated using a 14C-insecticide labelled at the O -CH 3 group. Following i.p. administration of the toxicant, [7- 14 C]methylguanine could be isolated from liver nucleic acids o f treated mice. The amount of 14C-label reached its maximum 6 h following administration of the insecticide. At maximum 14 C-labelling, the amount of 7-m ethylguanine calculated as fraction o f applied dose, was 20-22 x 10-4 and 98 -104 x -4, for DNA and RNA, respectivel The results obtained indicate also, that an appreciable amount of I4C-activity is incorporated via the C -l pool. © 1987, Walter de Gruyter. All rights reserved.