No measurable increase in thymidine glycol or 8-hydroxydeoxyguanosine in liver DNA of rats treated with nafenopin or choline-devoid low-methionine diet.
Male rats were treated for 2 months with 1000 ppm nafenopin in the diet or for 4 or 7 days with a choline-devoid low-methionine diet. DNA was isolated from the livers and analyzed for the presence of cis-thymidine glycol-3'-phosphate (cis-dTGp) by 32P-postlabeling and for the level of 8-hydroxy-deoxyguanosine (8-OH-dG) by electrochemical detection (ECD). In no DNA sample was the level of cis-dTGp above the limit of detection of 1 modified thymidine per 10(6) nucleotides. With 8-OH-dG, a background level of this modification of 20 8-OH-dG per 10(6) nucleosides was found in liver DNA of control rats, which was not affected by either treatment. It is postulated for thymidine glycol that a potential increase was below the limit of detection or was rapidly repaired in vivo and that the steady-state level of endogenous 8-hydroxydeoxyguanosine appears not to be influenced by the treatments chosen.
Hegi
M E
ME
Institute of Toxicology, Swiss Federal Institute of Technology, Zurich.
Ulrich
D
D
Sagelsdorff
P
P
Richter
C
C
Lutz
W K
WK
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D002796:Choline Deficiency / Q000378:metabolism*; D004247:DNA / Q000187:drug effects / Q000378:metabolism*; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000032:analysis; D004563:Electrochemistry; D008099:Liver / Q000378:metabolism; D008297:Male; D008715:Methionine / Q000172:deficiency / Q000502:physiology; D009255:Nafenopin / Q000494:pharmacology*; D011422:Propionates / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344; D013941:Thymine / Q000031:analogs & derivatives / Q000032:analysis
D011422:Propionates; D009255:Nafenopin; C029389:thymine glycol; D000080242:8-Hydroxy-2'-Deoxyguanosine; D004247:DNA; D008715:Methionine; D003849:Deoxyguanosine; D013941:Thymine