Kb. Kim et Bm. Lee, OXIDATIVE STRESS TO DNA, PROTEIN, AND ANTIOXIDANT ENZYMES (SUPEROXIDE-DISMUTASE AND CATALASE) IN RATS TREATED WITH BENZO(A)PYRENE, Cancer letters, 113(1-2), 1997, pp. 205-212
Oxidative DNA damage (as 8-hydroxydeoxyguanosine; 8-OHdG), carbonyl co
ntent of proteins, and activities of superoxide dismutase (SOD) and ca
talase were investigated in female Sprague-Dawley rats orally treated
with benzo(a)pyrene (B(a)P) (75 mg/rat). HPLC-ECD system showed that B
(a)P increased the level of 8-OHdG in tissues (liver, kidney, and lung
), but a statistical significance was observed only in the liver (3.5-
fold increase) and kidney (two-fold increase). In the liver, the peak
level (21 +/- 5 8-OHdG residues/10(5) dG) was obtained 12 h after trea
tment and returned close to control level (9 +/- 2 8-OHdG residues/10(
5) dG) at 24 h, but 8-OHdG was persistent in the kidney. Carbonyl cont
ents measured as an index of protein oxidation were slightly increased
(23 similar to 35%) in the cytosolic fraction of tissues, but a signi
ficant increase (2.19 nmol/mg protein, 35% increase) was observed only
in the liver 6 h after treatment, similar to 8-OHdG. However, the rat
e of increase was relatively low compared to that of 8-OHdG. In contra
st to DNA and protein damages, the activities of SOD and catalase in t
he tissues were decreased after treatment (P < 0.01) and gradually inc
reased to control levels. SOD and catalase activities in organs of rat
s were inversely correlated with oxidative damages to DNA and protein.
The data suggest that B(a)P oxidatively altered DNA, protein, and ant
ioxidant enzymes in rats and this might be associated with B(a)P carci
nogenesis. (C) 1997 Elsevier Science Ireland Ltd.