Henriette Brésil

TL;DR: The absorption spectra of the adducts were identical with that obtained by reaction of chloroethylene oxide with 4-(4-nitrobenzyl) pyridine, and a common product of these reactions was tentatively characterized as 3-β-ribofuranosyl-imidazo-[2,1- i ]purine.

TL;DR: The present results show that human liver has a significant capacity to repair O6-methylguanine in DNA, which has been implicated as a critical product in carcinogenesis and mutagenesis.

TL;DR: DNA synthesis was higher in the liver, kidney, and lung of rats receiving dimethylnitrosamine pretreatment, and the alkylation product ratios were closely similar in the two groups of animals at all times, whereas the O6-methylguanine:7-methylGuanine ratio was initially 3 timesHigher in the control animals and fell more slowly.

TL;DR: The results suggest that the lower amount of O 6-methylguanine found in hepatic DNA of rats pretreated with dimethylnitrosamine was due to an increased activity of the enzyme system responsible for this reaction, which could be the result of an induction or activation of the enzymes in response to the chronic administration of the carcinogen.

TL;DR: The results suggest that the activity of certain DNA repair enzymes can be modulated by environmental exposure.