title: Theophylline-induced increase in plasma uric acid--purine catabolism increased by theophylline.
abstract: The effect of theophylline on the concentration of uric acid in plasma was investigated. Theophylline increased the plasma concentrations of purine bases (uric acid, hypoxanthine and xanthine) without a decreased urinary excretion of these purine bases in normal subjects. 1-methyl uric acid, a metabolite of theophylline, was not converted to uric acid in a detectable level by the hepatoma-derived cell line HuH-7 cells. Although theophylline affected neither the concentration of nucleotides nor the activities of the enzymes related to purine metabolism (hypoxanthine-guanine phosphoribosyl transferase, 5'-nucleotidase, adenosine deaminase and purine nucleoside phosphorylase) in erythrocytes, these results suggested that theophylline-induced purine degradation seems to be a cause of the increased concentration of uric acid in plasma.
authors.affiliation: Third Department of Internal Medicine, Hyogo College of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Moriwaki
authors.forename: M
authors.initials: M
authors.lastname: Suda
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.forename: K
authors.initials: K
authors.lastname: Hiroishi
authors.forename: K
authors.initials: K
authors.lastname: Higashino
mesh_terms: D000284:Administration, Oral; D000328:Adult; D004912:Erythrocytes / Q000378:metabolism; D006801:Humans; D019271:Hypoxanthine; D007042:Hypoxanthines / Q000097:blood / Q000652:urine; D008297:Male; D009711:Nucleotides / Q000097:blood; D011687:Purines / Q000378:metabolism*; D013806:Theophylline / Q000008:administration & dosage / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D014527:Uric Acid / Q000031:analogs & derivatives / Q000097:blood* / Q000652:urine; D019820:Xanthine; D014970:Xanthines / Q000097:blood / Q000652:urine
chemical_list: D007042:Hypoxanthines; D009711:Nucleotides; D011687:Purines; D014970:Xanthines; D019820:Xanthine; D014527:Uric Acid; D019271:Hypoxanthine; D013806:Theophylline