title: Vanadium pharmacokinetics and oral bioavailability upon single-dose administration of vanadyl sulfate to rats.
abstract: Vanadium pharmacokinetic parameters and oral bioavailability were determined after administration of vanadyl sulfate, an antidiabetic agent, to male Wistar rats. An optimal sampling design was used over a 21-day period; vanadium was measured in blood by atomic absorption spectrophotometry (AAS). After i.v. bolus injection (3.025 mg V/kg body weight), a three-compartment model was fitted to the data. Mean (+/- SD) half-lives were 0.90 +/- 0.56 hours, 24.8 +/- 14.5 h and 201 +/- 74 h, respectively, for the three phases observed. Vanadium clearance averaged 37.6 +/- 15.8 mL/h. Initial volume of distribution was 2.43 +/- 1.22 L/kg whereas total volume of distribution was 25.4 +/- 3.9 L/kg; these values largely exceeded body weight (i.e. 300 g), in agreement with a great uptake and retention of vanadium in tissues. After oral gavage administration (15.12 and 7.56 mg V/kg body weight), vanadium disposition was best described by a three-compartment model, with absorption appearing to occur by a zero-order rate. This process lasted 10.3 +/- 1.3 h and 10.9 +/- 1.1 h for the two dosage levels, respectively. Half-lives corresponding to the terminal log-linear part of the curve were 173.5 +/- 1.6 h and 172 +/- 6 h (Bayesian estimates). No dose-dependency was observed for any of the parameters determined. Absolute bioavailabilities, with reference to the i.v. administration, were 12.5% and 16.8% when determined from AUCmod. Bioavailability appeared to be higher than generally stated in the literature.
authors.affiliation: EA2987: Laboratoire de Pharmacologie et Physiopathologie Expérimentales, Faculté de Pharmacie, 34093 Montpellier Cedex 5, France.
authors.forename: J
authors.initials: J
authors.lastname: Azay
authors.forename: J
authors.initials: J
authors.lastname: Brès
authors.forename: M
authors.initials: M
authors.lastname: Krosniak
authors.forename: P L
authors.initials: PL
authors.lastname: Teissedre
authors.forename: J C
authors.initials: JC
authors.lastname: Cabanis
authors.forename: J J
authors.initials: JJ
authors.lastname: Serrano
authors.forename: G
authors.initials: G
authors.lastname: Cros
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D007275:Injections, Intravenous; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013054:Spectrophotometry, Atomic; D017968:Vanadium Compounds / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D007004:Hypoglycemic Agents; D017968:Vanadium Compounds; C034028:vanadyl sulfate