Fibrin Deposition and Removal in Disseminated Intravascular Coagulation Induced by Endotoxin and Saline Loading: Radioautographic Findings in Rats

In rats a single injection of endotoxin followed by an infusion of normal saline induced the generalized Shwartzman reaction. The presence of disseminated intravascular coagulation (DIC) was demonstrated by measuring plasma fibrinogen, platelet counts, schistocytes, plasma haemoglobin, fibrin(ogen) degradation products, and fibrin thrombi in the glomerular capillaries, 125I-fibrinogen was given after triggering DIC in order to examine the fibrinogen turnover in plasma and the kinetics of fibrin deposition and removal in kidney, liver, and spleen. 125I-fibrinogen turnover was found to be highly accelerated. Early deposition and removal were observed in the kidneys, while a later peak with a more delayed fall of radioactivity was noted in liver and spleen. On histological examination fibrin could be seen only in the glomerular capillaries and only in the early phase of DIC. In radioautographs radioactive material was localized in the glomerular capillaries, the Kupffer' cells of the liver, and in the perifollicular macrophages of the spleen. Comparing the results obtained by scintillation counting to those obtained by light microscopy it can be assumed that radioactivity in kidneys is correlated to fibrin deposition in glomerular capillaries and to an accumulation on fibrin(ogen) degradation products in liver and spleen.