Plasma cathepsin activity and reticuloendothelial phagocytic function during hemorrhagic shock.

The present study evaluated two forms of hemorrhagic shock in terms of changes in plasma lysosomal enzyme activity, reticuloendothelial system (RES) phagocytic function, and plasma opsonic activity. Hemorrhagic shock was induced in rats by withdrawal of a fixed volume of blood equivalent to 3% body weight or by maintaining the arterial blood pressure at 40--45 mm Hg. Plasma cathepsin activity did not increase until after one hour of hypotension, and was increased 2.7-fold two hours after a 3% body weight hemorrhage and 11-fold after two hours at a blood pressure of 40--45 mm Hg. Phagocytic index and plasma opsonic activity were decreased in animals reinfused at 0, 30, or 120 minutes following a 3% body weight hemorrhage and in animals reinfused 0, 30, and 90 minutes following hemorrhage to a blood pressure of 40 mm Hg. There was a strong temporal relationship between the changes in phagocytic index and plasma opsonic activity; however, the decrease in RES function occurred earlier than the increase in plasma lysosomal enzyme activity. These results suggest that the depression of RES function during shock may be mediated, in part, by a deficit in circulating opsonic activity and that RES depression occurs prior to shock-induced cellular injury during hemorrhagic shock.