Effect of different vitamin A status on carcinogen-induced DNA damage and repair enzymes in rats.
The effect of different vitamin A status on events following DNA damage by hepatocarcinogens was investigated in rats. Formation of single-strand breaks in nuclear DNA induced by aflatoxin B1 and N-nitrosodimethylamine was observed to be more pronounced after vitamin A-deficiency. This enhanced damage was reversed upon vitamin A supplementation. Subsequent to DNA damage, the induction of repair enzymes poly(ADP-ribose) polymerase, DNA polymerase beta and DNA ligase was found to be significantly higher in vitamin A-deficient rats. Vitamin A supplementation brought down the induction to the levels found in rats maintained on normal diet. Vitamin A thus may control carcinogenesis by manipulating molecular events at the initiation stage.
Webster
R P
RP
Radiation Biology and Biochemistry Division, Bhabha Atomic Research Centre, Bombay, India.
Gawde
M D
MD
Bhattacharya
R K
RK
D016604:Aflatoxin B1 / Q000494:pharmacology; D000818:Animals; D016587:Antimutagenic Agents / Q000494:pharmacology*; D002273:Carcinogens / Q000633:toxicity*; D004249:DNA Damage; D011088:DNA Ligases / Q000096:biosynthesis*; D004256:DNA Polymerase I / Q000096:biosynthesis*; D004260:DNA Repair; D004128:Dimethylnitrosamine / Q000494:pharmacology; D004790:Enzyme Induction; D008297:Male; D011065:Poly(ADP-ribose) Polymerases / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D014801:Vitamin A / Q000494:pharmacology*; D014802:Vitamin A Deficiency
D016587:Antimutagenic Agents; D002273:Carcinogens; D014801:Vitamin A; D016604:Aflatoxin B1; D011065:Poly(ADP-ribose) Polymerases; D004256:DNA Polymerase I; D011088:DNA Ligases; D004128:Dimethylnitrosamine