CHANGES OF CIRCULATING BLOOD ENDOTOXIN ANALYZED BY QUANTITATIVE ASSAY AFTER INTRAVENOUS ADMINISTRATION OF ENDOTOXIN

Abstract

In platelet-rich plasma of rats and mongrel dogs, added endotoxin was determined by quantitative endotoxin assay using synthetic chromogenic substrate with perchloric acid pretreatment. By this method, the quantitative assay of endotoxin was proved to be relatively accurate.
Dynamic chages of circulating blood endotoxin were examined after intravenous administration of 0.5, 5 and 50μg/kg of endotoxin in 5 mongrel dogs. When 0.5μg/kg was administered, there was no remarkable changes. However, when 5 and 50μg/kg were administered, approximately 99.8 to 99.9% of administered endotoxin disapeared within 5 minutes, then followed a slower clearance rate with a mean half life of 21.4 and 10.3 minutes respectively. Though, when 500μg/kg was administered, also approximately 99.8 to 99.9% of administered endotoxin disappeared within 5 minutes, rapid clearance was shown till 30 minutes. Then, from 30 minutes to 3 hours, it was slowly clearanced, but after 3 hours there were no remarkable changes and approximately 50 to 500pg/ml of endotoxin was still found after 12 hours.