title: Nonsteroidal anti-inflammatory drugs inhibit gastric peroxidase activity.
abstract: The peroxidase activity of the mitochondrial fraction of rat gastric mucosa was inhibited with various nonsteroidal anti-inflammatory drugs (NSAIDs) in vitro. Indomethacin was found to be more effective than phenylbutazone (PB) or acetylsalicylic acid (ASA). Mouse gastric peroxidase was also very sensitive to indomethacin inhibition. Indomethacin has no significant effect on submaxillary gland peroxidase activity of either of the species studied. Purified rat gastric peroxidase activity was inhibited 75% with 0.15 mM indomethacin showing half-maximal inhibition at 0.04 mM. The inhibition could be withdrawn by increasing the concentration of iodide but not by H2O2. NSAIDs inhibit gastric peroxidase activity more effectively at acid pH (pH 5.2) than at neutral pH. Spectral studies showed a bathochromic shift of the Soret band of the enzyme with indomethacin indicating its interaction at or near the heme part of the enzyme.
authors.affiliation: Department of Physiology, Indian Institute of Chemical Biology, Calcutta.
authors.forename: R K
authors.initials: RK
authors.lastname: Banerjee
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001241:Aspirin / Q000494:pharmacology; D005753:Gastric Mucosa / Q000201:enzymology* / Q000648:ultrastructure; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007213:Indomethacin / Q000494:pharmacology; D007784:Lactoperoxidase / Q000037:antagonists & inhibitors; D051379:Mice; D008807:Mice, Inbred BALB C; D008928:Mitochondria / Q000201:enzymology; D009195:Peroxidase / Q000037:antagonists & inhibitors*; D010653:Phenylbutazone / Q000494:pharmacology; D011193:Potassium Iodide / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D011193:Potassium Iodide; D006861:Hydrogen Peroxide; D007784:Lactoperoxidase; D009195:Peroxidase; D010653:Phenylbutazone; D001241:Aspirin; D007213:Indomethacin