Vp. Palace et al., OXIDATIVE STRESS IN LAKE STURGEON (ACIPENSER-FULVESCENS) ORALLY EXPOSED TO 2,3,7,8-TETRACHLORODIBENZOFURAN, Aquatic toxicology, 35(2), 1996, pp. 79-92
Juvenile lake sturgeon were orally dosed with gelatin containing nomin
al concentrations of 0, 0.16 or 1.6 ng [H-3]-2,3,7,8-tetrachlorodibenz
ofuran (TCDF) kg(-1) fish weight. Liver, kidney and blood were collect
ed 10 and 27 days after exposure. Phase I mixed-function oxidase (MFO)
and Phase II (glucuronyltransferase) enzyme activities were determine
d in liver. Concentrations of non-enzymatic (tocopherol, retinoids) an
d enzymatic (superoxide dismutase, catalase, glutathione peroxidase) a
ntioxidant parameters were also quantified in liver and kidney. TC DF
concentrations were elevated in liver and kidney of both dose groups a
t 10 and 27 days. Lower tissue concentrations of TCDF at 27 days, comp
ared with 10 day exposures, as well as the presence of polar metabolit
es in bile, may indicate rapid metabolism and clearance of the contami
nant. MFO enzyme activity, measured as ethoxyresorufin-O-deethylase (E
ROD), was induced in liver with activity at the two sample periods ref
lecting the TCDF concentrations. Greater concentrations of hepatic lip
id peroxides in both dose groups, indicate that oxidative stress was p
roduced by contaminant exposure and/or induced metabolism enzyme activ
ity.