The antioxidant action of human extracellular fluids. Effect of human serum and its protein components on the inactivation of alpha 1-antiproteinase by hypochlorous acid and by hydrogen peroxide.
The elastase-inhibitory capacity of purified human alpha 1-antiproteinase is inactivated by low concentrations of the myeloperoxidase-derived oxidant hypochlorous acid, but much higher concentrations are required to inhibit the elastase-inhibitory capacity of serum samples. The protective effect of serum appears to be largely due to albumin. High concentrations of H2O2 also inactivate the elastase-inhibitory capacity of alpha 1-antiproteinase, by a mechanism not involving formation of hydroxyl radicals. Serum offers protection against H2O2 inactivation of alpha 1-antiproteinase. The relevance of these results to the tissue damage produced by activated phagocytes is discussed.
D001769:Blood / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D006997:Hypochlorous Acid / Q000494:pharmacology*; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors; D012709:Serum Albumin / Q000378:metabolism; D000515:alpha 1-Antitrypsin / Q000037:antagonists & inhibitors*
D001798:Blood Proteins; D012709:Serum Albumin; D000515:alpha 1-Antitrypsin; D006997:Hypochlorous Acid; D006861:Hydrogen Peroxide; D010196:Pancreatic Elastase