Distribution and Clearance of Circulating Endotoxin.

To elucidate the mechanisms of endotoxin action the distribution and clearance of injected endotoxin were studied in New Zealand white rabbits; some animals were rendered tolerant through successive (5 days) doses of endotoxin (E. coli lipopolysaccharide) and the remainder were nontolerant. Blood and plasma clearance of small doses of chromium-labeled endotoxin was more rapid in tolerant than in nontolerant rabbits. In both groups clearance was nearly complete within 10 minutes after injection. Circulating endotoxin was distributed between plasma and platelets in both non- and tolerant animals. A minimal amount of endotoxin was found in leukocytes by this was believed the result of contaminating platelets.