Increased serum catalase activity in rats subjected to thermal skin injury.

We found that rats subjected to thermal skin injury (burn) had increased serum hydrogen peroxide (H2O2) scavenging activity, serum catalase activity, erythrocyte (RBC) fragility, and edematous lung injury (lung leak) when compared to sham-treated rats. Serum H2O2 scavenging activity was inhibited by addition of sodium azide, a catalase inhibitor. Treatment of rats with the oxygen radical scavenger, dimethylthiourea (DMTU), decreased RBC fragility and lung leak but did not alter increased H2O2 scavenging or catalase activity of serum from rats subjected to skin burn. We conclude that increased serum catalase activity is a consequence of thermal skin injury and that increased serum catalase activity may be a mechanism that modulates H2O2-dependent processes following skin burn.