Disseminated intravascular coagulation induced by liquoid in the rat. I. Correlation of hematologic and complement abnormalities with renal lesions studied by light, fluorescence, and electron microscopy.

Under the proper experimental conditions, disseminated intravascular coagulation,"an intermediary mechanism of disease," results in the classic endotoxin-induced generalized Shwartzman reaction. Other substances, such as liquoid, a highly negatively charged anticoagulant, trigger a generalized Shwartzman reaction-like phenomenon in rabbits. We studied the effects of a single high intravenous dose of liquoid (12.5 mg.) upon the rat's coagulation and complement systems and their correlation with the kidney morphology by light, fluorescence, and electron microscopy. Thrombin time was prolonged; fibrinogen, plasminogen, and factors VIII and XII concentrations were markedly decreased, whereas fibrin degradation products were increased in the experimental animals when compared with the saline-injected controls (p greater than 0.001). Total hemolytic complement, hemolytic activity of terminal components (C3 to C9), and C3 protein concentration were significantly reduced (p greater than 0.001). The liquoid-injected rats developed cortical necrosis and manifested oliguria and anuria, with elevated blood urea nitrogen levels, when survival was longer than 3 hours. Histologically, thrombi of fibrin-like material filled the glomerular capillaries. Deposits of fibrin, and also of immunoglobulin G and C3, were readily identifiable by specific immunofluorescence, Linear or granular fluorescent deposits (or both) along the glomerular basement membranes and in the mesangium were observed. Electron microscopy demonstrated necrosis of glomeruli and abundant thrombi of fluffy, compact granular, or fibrillar electron-dense material. No typical fibrin periodicity was detected. These experiments support the concept of activation of the coagulation and the complement systems. We postulate that liquoid produced not only a consumptive coagulopathy in the rat but also a direct or perhaps anindirect activation of complement. Whether this latter has occurred through the classic or an alternate pathway remains to be elucidated.