The role of tissue fibrinolysis, lysosomal enzymes and lipid peroxidation on the hemorrhagic necrosis of digestive mucosa was investigated using experimental models of DIC (disseminated intravascular ...coagulation), hemorrhagic shock and mesenteric occlusion in the dogs. The experimental model of DIC was produced by intravenous administration of bacterial lipopolysaccharide (endotoxin), hemorrhagic shock by withdrawing blood from the femoral artery through cannula, keeping the arterial pressure between 50 and 60mmHg, and mesenteric occlusion by ligating the intestinal artery. The fibrinolytic activity and the lysosomal enzymatic activity, beta-glucuronidase and acid phosphatase, in the biopsied digestive mucosa revealed marked elevation following the administration of endotoxin, withdrawal of blood and ligation of the intestinal artery, to which the changes of the lipid peroxide value were found to be correlated. These data led us to conclude that the lipid peroxidation due to the ischemic change damages the lysosomal membrane followed by the release of an array of hydrolytic enzymes including plasminogen activator to bring about cell damage. The results allow to conclude that the lipid peroxidation plays an important role in the pathogenesis of ischemic colitis.
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