Characteristics of the hepatic monooxygenase system of the goldfish (Carassius auratus) and its induction with beta-naphthoflavone.
Treatment of goldfish with beta-naphthoflavone (ip) resulted in induction of hepatic monooxygenase activity in a dose-dependent manner. Levels of 7-ethoxyresorufin-O-deethylase and mexacarbate NADPH-dependent oxidative metabolism as well as cytochrome(s) P-450 were increased. Other substrates which have been associated with 3-methylcholanthrene (3-MC)-type induction in mammals were unchanged as was delta-aminolevulinic acid synthetase. Enzyme activities were inhibited by carbon monoxide and piperonyl butoxide confirming their cytochrome P-450 nature. NADH was found to stimulate metabolism in a significant manner with NADPH. pH-dependent ethyl isocyanide binding characteristics were similar in control and induced preparations while mexacarbate binding to oxidized microsomes revealed a higher apparent affinity constant (Kapps) as well as greater overall binding in induced preparations. SDS-gel electrophoresis revealed an increased band with a molecular weight of approximately 56,000.
D000818:Animals; D001571:Benzoflavones / Q000494:pharmacology*; D003530:Cyprinidae / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology*; D006054:Goldfish / Q000378:metabolism*; D008862:Microsomes, Liver / Q000201:enzymology*; D010105:Oxygenases / Q000096:biosynthesis*; D013057:Spectrum Analysis; D019324:beta-Naphthoflavone
D001571:Benzoflavones; D005419:Flavonoids; D019324:beta-Naphthoflavone; D010105:Oxygenases