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 prot eins, including proteolytic enzymes and their inhibitors. The activity of c athepsin G and elastase and their inhibitors such as alpha-1-antitrypsin an d 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 d ose. At the same time, activity of their inhibitors was reduced. Methanol i ngestion in humans caused changes in activities of proteases and their inhi bitors with similar direction as in rats. These changes in activity of prot eases and their inhibitors produce significant disturbances in proteolytic- antiproteolytic balance after methanol administration.