title: Estimation of aldehyde oxidase activity in vivo from conversion ratio of N1-methylnicotinamide to pyridones, and intraspecies variation of the enzyme activity in rats.
abstract: The in vivo conversion ratio of N1-methylnicotinamide (NMN) to N1-methyl-2-pyridone-5-carboxamide (2-PY) and N1-methyl-4-pyridone-3-carboxamide (4-PY) as a parameter for the estimation of aldehyde oxidase level in rats was examined. NMN and its pyridones (2-PY and 4-PY) are usually detected in the urine of rats. When we measured the ratio of the amount of pyridones to the total amount of NMN and pyridones (RP value) in the urine of rats, marked intraspecies variations were observed. The variation in RP value among strains was closely related to the differences of liver aldehyde oxidase activity measured with NMN as a substrate. RP values after administration of NMN to different strains of rats confirmed the existence of strain differences of aldehyde oxidase activity in vivo. We demonstrated that measurements of NMN and its pyridones usually excreted in the urine can be used to predict the in vivo level of aldehyde oxidase.
authors.affiliation: Division of Medicinal Chemistry, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Sugihara
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Tayama
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Shimomiya
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yoshimoto
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ohta
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Kitamura
mesh_terms: D042931:Aldehyde Oxidase / Q000378:metabolism*; D000818:Animals; D008099:Liver / Q000201:enzymology; D008297:Male; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000652:urine; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity
chemical_list: D009536:Niacinamide; C016590:N(1)-methyl-4-pyridone-5-carboxamide; C005211:N'-methyl-2-pyridone-5-carboxamide; D042931:Aldehyde Oxidase; C024058:N(1)-methylnicotinamide