A humoral reticuloendothelial-depressing substance in shock

Abstract

The granulopectic activity of the reticuloendothelial system was assessed by measuring the clearance of carbon particles from the blood of splenectomized, normotensive "assay" dogs. When such animals were cross transfused with portal venous blood from splenectomized, normotensive "experimental" animals, there was a small decline (K1 – K2 = 0.0060) in the phagocytic index. However, when experimental dogs were subjected to hemorrhagic hypotension (mean arterial pressure of 40 mm Hg for 90 min), cross transfusion of portal venous blood to the assay animal resulted in a very marked ( P < 0.001) depression in phagocytic activity (K1 – K2 = 0.0218). On the other hand, cross transfusion of femoral artery blood from experimental dogs subjected to hemorrhagic hypotension caused only a slight decline in the phagocytic index of the assay animals (K1 – K2 = 0.0051). The results strongly suggest that a humoral reticuloendothelial-depressing substance is present in the portal venous blood, but not in the femoral arterial blood, of dogs subjected to hemorrhagic hypotension. This substance is probably formed in the gastrointestinal tract in response to hypotension.