title: Superoxide production by polymorphonuclear leucocytes in rheumatoid arthritis and osteoarthritis: in vivo inhibition by the antirheumatic drug piroxicam due to interference with the activation of the NADPH-oxidase.
abstract: The superoxide (O2-) production of stimulated polymorphonuclear leucocytes is increased in patients with rheumatoid arthritis and osteoarthritis compared with controls. Treatment of these different groups with pharmacological amounts of the non-steroidal anti-inflammatory drug piroxicam in vivo resulted in a decrease of about 25% in O2- secretion by isolated granulocytes. In vitro experiments showed that piroxicam inhibits O2- production of granulocytes by interference with the stimulation of the NADPH-oxidase. Piroxicam caused diminished O2- production of membrane fragments if it was present during the stimulation of the NADPH-oxidase of the intact cells. During the actual O2- production of the stimulated membrane fragments piroxicam had no effect. It is concluded that piroxicam is able to inhibit granulocyte O2- production by blocking the activation of NADPH-oxidase, which results in diminished tissue destruction by oxygen free radicals in inflammatory diseases.
mesh_terms: D001168:Arthritis / Q000097:blood*; D001172:Arthritis, Rheumatoid / Q000097:blood; D006801:Humans; D009247:NADH, NADPH Oxidoreductases / Q000097:blood*; D019255:NADPH Oxidases; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010003:Osteoarthritis / Q000097:blood; D010894:Piroxicam; D013481:Superoxides / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013843:Thiazines / Q000494:pharmacology*
chemical_list: D013843:Thiazines; D013481:Superoxides; D010894:Piroxicam; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; D013755:Tetradecanoylphorbol Acetate