title: Zonal distribution of allopurinol-oxidizing enzymes in rat liver.
abstract: We describe an enzymatic histochemical localization of two allopurinol-oxidizing enzymes, xanthine oxidase and aldehyde oxidase in rat hepatic tissues. This method is based on the tetrazolium salt procedures by use of a tissue protectant, polyvinyl alcohol, with tetra-nitro BT as the final electron acceptor. The present study demonstrated that both oxidases are present in the cytoplasm of hepatic cells. However, the distribution of the enzymes was uneven, being seen mainly in the pericentral rather than the periportal area. When allopurinol was used as a substrate, the specific staining by xanthine oxidase was more prominent than that of aldehyde oxidase. The results suggested that xanthine oxidase is more effective in oxidizing allopurinol than aldehyde oxidase.
authors.affiliation: Third Department of Internal Medicine, Hyogo College of Medicine Mukogawa-cho 1-1, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Moriwaki
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: J
authors.initials: J
authors.lastname: Yamakita
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.forename: Z
authors.initials: Z
authors.lastname: Tsutsumi
authors.forename: K
authors.initials: K
authors.lastname: Higashino
mesh_terms: D042931:Aldehyde Oxidase; D000445:Aldehyde Oxidoreductases / Q000032:analysis*; D000493:Allopurinol / Q000378:metabolism*; D000818:Animals; D006651:Histocytochemistry; D008099:Liver / Q000166:cytology / Q000201:enzymology*; D008297:Male; D010084:Oxidation-Reduction; D051381:Rats; D017208:Rats, Wistar; D014969:Xanthine Oxidase / Q000032:analysis*
chemical_list: D000493:Allopurinol; D014969:Xanthine Oxidase; D000445:Aldehyde Oxidoreductases; D042931:Aldehyde Oxidase