Effects of hemorrhagic shock and retransfusion on catalase and superoxide dismutase activities in rabbits.

: The effects of hemorrhagic shock and retransfusion on the activities of two endogenous antioxidant enzymes, catalase and superoxide dismutase, were studied in male New Zealand white rabbits. Following instrumentation and stabilization, blood was withdrawn to reduce mean arterial pressure to 35 mmHg (SHOCK). After 60 min of shock, the warmed autologous blood was infused and the animals were allowed to recover for an additional 30 min (RETRANS). CONTROL animals were instrumented but not bled or transfused. A 60 min period of hemorrhagic shock had no significant effect on tissue or plasma activities of catalase or superoxide dismutase. However, transfusion following hemorrhagic shock resulted in an increase in catalase activity of nearly two-fold in the liver and five-fold in the small intestine. In contrast, superoxide dismutase activity remained unchanged after retransfusion in other tissues and in plasma. These results indicate that superoxide dismutase and catalase activities may be preserved or even induced following transfusion for hemorrhagic shock.