[Brain injury induced by continuous infusion of endotoxin (ET) in rat--relationship between ET infusion hours and development of cerebral and visceral lesions].

Experimental generalized Shwartzman reaction (GSR) in animals can be induced by systemic injection of bacterial endotoxin lipopolysaccharide (ET) and presents with thrombotic occlusions of small blood vessels in different organs analogous to disseminated intravascular coagulation (DIC) in man. It is known that DIC involvement of the central nervous system (CNS) in man presents with grave prognosis, but there is a paucity of information concerning CNS involvement in animals with ET induced GSR. In order to better understand the pathogenesis of CNS involvement of DIC in man, and to search for better prophylactic and therapeutic measures against DIC, animal model of DIC was induced by continuous intravenous infusion of E coli ET. A total of 56 male Donryu rats were divided into 6 groups and infused with physiologic saline (controls) and ET lipopolysaccharide at 88.5 micrograms/hour. The rats were killed at 6 different intervals from 24 to 160 hours and examined postmortem. Intracerebral hemorrhagic lesions were seen in 2 of 7 rats (29%) as early as 24 hours of ET-infusion and increased to 77% to 87% of rats receiving continuous ET infusion up to 160 hours. Formation of fibrin thrombi was uncommon in intracerebral blood vessels, but it was frequently observed in choroid plexus capillaries. Fibrin thrombi in other viscera (heart, lungs, liver, kidneys, spleen) were common but decreased toward the end of 160-hour infusion period. Results of this study showed that a continuous intravenous infusion of large dose ET lipopolysaccharide in rats produces intracerebral hemorrhagic lesions analogous to DIC changes of brain seen in man.(ABSTRACT TRUNCATED AT 250 WORDS)