The in vivo and in vitro oxidation of molecular form 1 of biliverdin reductase to molecular form 3 by diamide.
Administration of phenylhydrazine to rats converted molecular form 1 of the liver biliverdin reductase into its disulfide bridged dimer (molecular form 3). This oxidative dimerization was shown not to be mediated by the NAD(+)-dependent dehydrogenase [(1984) Biochem. Biophys. Res. Commun. 121, 249-254]. Administration of diamide produced the same conversion. Although hepatic levels of GSH also decreased, no mixed disulfides of the reductase and GSH could be detected. Administration of the antioxidants allopurinol and alpha-tocopherol together with the diamide did not affect this conversion of molecular forms produced by the latter. The diamide also oxidized molecular form 1 of biliverdin reductase in vitro and molecular form 3 was formed. The chemical oxidation took place at a high rate and was partially inhibited by GSH but not by cysteine.
Tomaro
M L
ML
Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina.
Frydman
J
J
Frydman
R B
RB
D000818:Animals; D001391:Azo Compounds / Q000494:pharmacology*; D003958:Diamide / Q000494:pharmacology*; D005260:Female; D005978:Glutathione / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D046911:Macromolecular Substances; D008970:Molecular Weight; D010088:Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism*; D044925:Oxidoreductases Acting on CH-CH Group Donors; D010659:Phenylhydrazines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values
D001391:Azo Compounds; D046911:Macromolecular Substances; D010659:Phenylhydrazines; D003958:Diamide; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; C019789:biliverdin reductase; D005978:Glutathione