title: Postnatal development of hepatic xanthine oxidase in baby pigs and turnover of purine catabolites at reduced ambient temperature.
abstract: 1. The activity of xanthine oxidase in liver samples of baby pigs up to 4 weeks of age was investigated. On the 3rd day of life the turnover of hypoxanthine and of uric acid were measured after intravenous injection of 3H- and 14C-labelled tracers into animals kept at normal (32 degrees C) and reduced (20 degrees C) ambient temperature. 2. Hepatic xanthine oxidase activity increased progressively from 2 to 28 days of age (r = 0.689; P < 0.001). The increase of Vmax and of KM within 3-4 weeks was about 4.5-fold. 3. In 3-day-old baby pigs kept at normal temperature, pool size and turnover was about 10-fold higher for hypoxanthine than for uric acid. 4. At reduced ambient temperature, the pool size of uric acid increased 3.9-fold (P < 0.01) and turnover 1.6-fold (P < 0.05). For hypoxanthine the increases were insignificant.
authors.affiliation: Institut für Physiologie, Physiologische Chemie und Ernährungsphysiologie, Universität München, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Giesecke
authors.forename: G
authors.initials: G
authors.lastname: Heiss
authors.forename: W
authors.initials: W
authors.lastname: Erhardt
authors.forename: R
authors.initials: R
authors.lastname: Rosskopf
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D003080:Cold Temperature / Q000009:adverse effects; D019271:Hypoxanthine; D007042:Hypoxanthines / Q000378:metabolism; D007674:Kidney Diseases / Q000209:etiology / Q000378:metabolism / Q000662:veterinary; D007700:Kinetics; D008099:Liver / Q000254:growth & development / Q000378:metabolism*; D011687:Purines / Q000378:metabolism*; D013552:Swine; D013553:Swine Diseases / Q000209:etiology / Q000378:metabolism; D014527:Uric Acid / Q000378:metabolism; D014969:Xanthine Oxidase / Q000378:metabolism*
chemical_list: D007042:Hypoxanthines; D011687:Purines; D014527:Uric Acid; D019271:Hypoxanthine; D014969:Xanthine Oxidase