title: ATPase and Adpase activities in synovial membrane of equine metacarpophalangeal joint.
abstract: ATPase and ADPase activities capable of hydrolyzing nucleoside di- and triphosphates in the presence of Ca2+ are present in synovial membrane of metacarpophalangeal joint mainly associated to membrane fractions. These hydrolytic activities have been considered involved in the inflammatory process where ATP and ADP are inflammatory mediators while adenosine counteracts this effect. Both, subcellular localization and kinetic properties of these nucleotidase activities, suggest that could correspond to single enzyme called ATP-diphosphohydrolase or apyrase. The comparison of the activity on ATP-Ca and ADP-Ca from normal and pathological equine synovial membrane did not show significant differences either in the subcellular fraction distribution or in the enrichment of each subcellular fraction. Neither differences on 5'-nucleotidase activity present in the microsomal fraction were observed.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago.
authors.forename: Paula A
authors.initials: PA
authors.lastname: Jiménez
authors.forename: Lorena
authors.initials: L
authors.lastname: García
authors.forename: H
authors.initials: H
authors.lastname: Adarmes
authors.forename: E
authors.initials: E
authors.lastname: González
authors.forename: M A
authors.initials: MA
authors.lastname: Valenzuela
mesh_terms: D015720:5'-Nucleotidase / Q000378:metabolism; D000241:Adenosine / Q000096:biosynthesis; D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D001081:Apyrase / Q000009:adverse effects / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001168:Arthritis / Q000201:enzymology; D003600:Cytosol / Q000187:drug effects / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006736:Horses / Q000378:metabolism*; D066298:In Vitro Techniques; D007596:Joints / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology; D013347:Subcellular Fractions / Q000201:enzymology; D013583:Synovial Membrane / Q000201:enzymology*
chemical_list: D004791:Enzyme Inhibitors; D015720:5'-Nucleotidase; D000251:Adenosine Triphosphatases; D001081:Apyrase; D000241:Adenosine