Metabolism and elimination of the endogenous DNA adduct, 3-(2-deoxy-beta-D-erythropentofuranosyl)-pyrimido[1,2-alpha]purine-10(3H)-one, in the rat.
Endogenously occurring damage to DNA is a contributing factor to the onset of several genetic diseases, including cancer. Monitoring urinary levels of DNA adducts is one approach to assess genomic exposure to endogenous damage. However, metabolism and alternative routes of elimination have not been considered as factors that may limit the detection of DNA adducts in urine. We recently demonstrated that the peroxidation-derived deoxyguanosine adduct, 3-(2-deoxy-beta-D-erythropentofuranosyl)-pyrimido[1,2-alpha]purine-10(3H)-one (M1dG), is subject to enzymatic oxidation in vivo resulting in the formation of a major metabolite, 6-oxo-M1dG. Based on the administration of [14C]M1dG (22 microCi/kg) to Sprague-Dawley rats (n=4), we now report that 6-oxo-M1dG is the principal metabolite of M1dG in vivo representing 45% of the total administered dose. When [14C]6-oxo-M1dG was administered to Sprague-Dawley rats, 6-oxo-M1dG was recovered unchanged (>97% stability). These studies also revealed that M1dG and 6-oxo-M1dG are subject to biliary elimination. Additionally, both M1dG and 6-oxo-M1dG exhibited a long residence time following administration (>48 h), and the major species observed in urine at late collections was 6-oxo-M1dG.
Knutson
Charles G
CG
A. B. Hancock, Jr. Memorial Laboratory for Cancer Research, Department of Biochemistry, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, USA.
Wang
Hao
H
Rizzo
Carmelo J
CJ
Marnett
Lawrence J
LJ
D000818:Animals; D001646:Bile / Q000378:metabolism*; D001648:Bile Canaliculi / Q000378:metabolism; D018736:DNA Adducts / Q000378:metabolism* / Q000494:pharmacology; D004249:DNA Damage / Q000502:physiology*; D016678:Genome / Q000502:physiology*; D008297:Male; D010084:Oxidation-Reduction; D011684:Purine Nucleosides / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
C491625:3-(2'-deoxy-beta-D-erythro-pentofuranosyl)pyrimido(1,2-alpha)purin-10(3H)-one; D018736:DNA Adducts; D011684:Purine Nucleosides