Activity of cathepsin G, elastase, and their inhibitors in plasma during methanol intoxication.

Methanol oxidation in the liver is accompanied by formation of formaldehyde and free radicals. These compounds can react with biologically active proteins, including proteolytic enzymes and their inhibitors. The activity of cathepsin G and elastase and their inhibitors such as alpha-1-antitrypsin and alpha-2-macroglobulin in plasma of rats given methanol orally in doses of 1.5, 3, and 6 g/kg was investigated for 7 days. The activity of cathepsin G and elastase was increased from 12 h to 5 d, proportionally to methanol dose. At the same time, activity of their inhibitors was reduced. Methanol ingestion in humans caused changes in activities of proteases and their inhibitors with similar direction as in rats. These changes in activity of proteases and their inhibitors produce significant disturbances in proteolytic-antiproteolytic balance after methanol administration.