Formation of a reticuloendothelial-depressing substance in the ischemic intestine

Abstract

The phagocytic index of the reticuloendothelial system of normotensive assay dogs was determined by measuring the clearance of carbon particles from the blood. These animals were cross-transfused with portal venous blood from experimental dogs bled to a mean arterial pressure of 40 mm Hg for 90 min. The superior mesenteric artery of the experimental animal was perfused at a normal rate of 8.8 ml/kg/min in half of the experiments and at a rate of 3.2 ml/kg/min (equivalent to rates prevailing in hemorrhagic hypotension) in the remaining experiments. Statistical comparison showed a significantly greater (P < 0.01) depression of reticuloendothelial activity in the group with lower flows. The results strongly suggest that a humoral reticuloendothelial-depressing substance is formed in the ischemic intestine of dogs subjected to hemorrhagic hypotension.