Reticuloendothelial system function and humoral factor deficiency following acute hemorrhage.

The present study has shown that following acute hemorrhage (equivalent to 3% body weight withdrawn over 20 min) in the rat, there is a large reduction (56% of control) in circulating alpha-2-glycoprotein opsonic activity. The reduction in this plasma opsonic activity was near maximal by the completion of blood withdrawal and was maintained throughout a 2-h hypotension period. There was no trend toward recovery of the opsonic activity when evaluated 15 min following reinfusion of shed blood in animals that were hypotensive for 0, 30, and 120 min. Reticuloendothelial system (RES) phagocytic function, as assessed from the carbon clearance rate (phagocytic index) following reinfusion of the shed blood, was depressed in animals that were hypotensive for 0, 30, and 120 min. Thus, phagocytic index followed a time course similar to the depression of opsonic activity. The observed close temporal relationship between alpha-2-glycoprotein opsonic deficiency and depression of RES clearance further supports the possible role of a humoral opsonic deficiency in mediating the RES phagocytic depression during circulatory shock.