title: In vitro oxidation of pyrazinamide and allopurinol by rat liver aldehyde oxidase.
abstract: Aldehyde oxidase was purified about 120-fold from rat liver cytosol by sequential column chromatography using diethylaminoethyl (DEAE) cellulose, Benzamidine-Sepharose 6B and gel filtration. The purified enzyme was shown as a single band with M(r) of 2.7 x 10(5) on polyacrylamide gel electrophoresis (PAGE) and M(r) of 1.35 x 10(5) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Using this purified enzyme, in vitro conversion of allopurinol, pyrazinamide and pyrazinoic acid was investigated. Allopurinol and pyrazinamide were oxidized to oxypurinol and 5-hydroxy-pyrazinamide, respectively, while pyrazinoic acid, the microsomal deamidation product of pyrazinamide, was not oxidized to 5-hydroxypyrazinoic acid. The apparent Km value of the enzyme for pyrazinamide was 160 microM and that for allopurinol was 1.1 mM. On PAGE, allopurinol- or pyrazinamide-stained band was coincident with Coomassie Brilliant Blue R 250-stained band, respectively. These results suggest that aldehyde oxidase may play a role in the oxidation of allopurinol to oxypurinol and that of pyrazinamide to 5-hydroxypyrazinamide with xanthine dehydrogenase which can oxidize both allopurinol and pyrazinamide in vivo. The aldehyde oxidase may also play a major role in the oxidation of allopurinol and pyrazinamide in the subgroup of xanthinuria patients (xanthine oxidase deficiency) who can oxidize both allopurinol and pyrazinamide.
authors.affiliation: Third Department of Internal Medicine, Hyogo College of Medicine, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Moriwaki
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Nasako
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.forename: M
authors.initials: M
authors.lastname: Suda
authors.forename: K
authors.initials: K
authors.lastname: Hiroishi
authors.forename: T
authors.initials: T
authors.lastname: Hada
authors.forename: K
authors.initials: K
authors.lastname: Higashino
mesh_terms: D042931:Aldehyde Oxidase; D000445:Aldehyde Oxidoreductases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D000493:Allopurinol / Q000378:metabolism*; D000818:Animals; D001550:Benzamidines / Q000494:pharmacology; D066298:In Vitro Techniques; D008099:Liver / Q000201:enzymology*; D008297:Male; D010084:Oxidation-Reduction; D010117:Oxypurinol / Q000378:metabolism; D011718:Pyrazinamide / Q000031:analogs & derivatives / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014227:Triazines / Q000494:pharmacology
chemical_list: D001550:Benzamidines; D014227:Triazines; C032191:5-hydroxypyrazinamide; D011718:Pyrazinamide; C072977:BOF 4272; D000493:Allopurinol; D000445:Aldehyde Oxidoreductases; D042931:Aldehyde Oxidase; D010117:Oxypurinol; C032157:benzamidine