title: Biochemical changes in arthritic rats: dehydroascorbic and ascorbic acid levels.
abstract: The objective of this work was to evaluate the use of vitamin C as a biomarker in the inflammatory phase of the rat adjuvant arthritis and to correlate it with other parameters used for disease evaluation. Paw swelling was used for physical evaluation and the levels of ascorbate and dehydroascorbate in the serum of male rats, before and after adjuvant arthritis induction, were quantified by a high-performance liquid chromatography method (HPLC). The optimised HPLC assay enabled the quantification of both forms of the vitamin in rat sera, with the same extraction method and using different detectors, instead of obtaining dehydroascorbate by subtraction of the total ascorbate measurement. This method was used to follow the severity of adjuvant arthritis and the results were correlated with other already established disease activity parameters. A decrease of ascorbic acid and dehydroascorbic acid was observed with the increase of right paw circumference during the course of adjuvant arthritis. The disease associated changes in the serum concentrations of ascorbic acid, from biosynthesis and from recycling, can be evaluated by the direct quantification of dehydroascorbic acid. This provides some evidence for the potential of the quantification of these biomarkers to study the disease activity, and as a tool for the establishment of therapeutic protocols, to evaluate the anti-inflammatory effect of new drugs or formulations.
authors.affiliation: UNFAB-DB, INETI, Edifício F, Estrada do Paço do Lumiar 22, 1649-038 Lisbon, Portugal. sandra.simoes@ineti.pt
authors.forename: Sandra I D
authors.initials: SI
authors.lastname: Simões
authors.forename: Carla V
authors.initials: CV
authors.lastname: Eleutério
authors.forename: M Eugénia M
authors.initials: ME
authors.lastname: Cruz
authors.forename: M Luísa
authors.initials: ML
authors.lastname: Corvo
authors.forename: M Bárbara F
authors.initials: MB
authors.lastname: Martins
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000097:blood*; D001205:Ascorbic Acid / Q000097:blood* / Q000737:chemistry; D003683:Dehydroascorbic Acid / Q000097:blood* / Q000737:chemistry; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D001205:Ascorbic Acid; D003683:Dehydroascorbic Acid