title: Altered vitamin B6 homeostasis during aminophylline infusion in the beagle dog.
abstract: The effect of intravenous infusion of aminophylline, a strong inhibitor of pyridoxal kinase, on intra- and extracellular vitamin B6 homeostasis was investigated in four beagle dogs. Plasma and erythrocyte pyridoxal levels increased by 118% and 117% respectively after 3 hours of aminophylline infusion, (4 mg/kg body weight/hour), however, infusion of beta-hydroxyethyltheophylline, which does not inhibit pyridoxal kinase, had no effect on either intra- or extracellular vitamin B6 aldehyde derivative levels. It is suggested that theophylline induced pyridoxal kinase inhibition resulted in a disturbed equilibrium between pyridoxal and pyridoxal 5'-phosphate.
authors.affiliation: Department of Chemical Pathology, University of Pretoria, South Africa.
authors.forename: R
authors.initials: R
authors.lastname: Delport
authors.forename: J B
authors.initials: JB
authors.lastname: Ubbink
authors.forename: H
authors.initials: H
authors.lastname: Bosman
authors.forename: S
authors.initials: S
authors.lastname: Bissbort
authors.forename: W J
authors.initials: WJ
authors.lastname: Vermaak
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood / Q000378:metabolism; D000628:Aminophylline / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000494:pharmacology; D004285:Dogs; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D006706:Homeostasis; D007262:Infusions, Intravenous; D011731:Pyridoxal Kinase / Q000037:antagonists & inhibitors; D011736:Pyridoxine / Q000097:blood / Q000378:metabolism*; D012709:Serum Albumin / Q000378:metabolism; D013806:Theophylline / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D001993:Bronchodilator Agents; D012709:Serum Albumin; D000628:Aminophylline; D013806:Theophylline; D011731:Pyridoxal Kinase; D000469:Alkaline Phosphatase; D011736:Pyridoxine; C008749:etofylline