The removal of 14C labeled endotoxin by activated charcoal

Endotoxin shock due to Gram-negative enteric bacteria is of major medical concern with an estimated 100,000 fatalities in the United States per year. An effective therapy for endotoxin shock, particularly in combination with significant liver damage, has not been available to date. Since activated charcoal is known as a universal sorbent, the use of activated charcoal in a hemoperfusion apparatus to remove endotoxin has interesting possibilities. Current assays for endotoxin are inadequate. The Limulus Amoebocyte Lysate (LAL) assay was found to give nonreproducible results within our range of requirements for accuracy. We, therefore, grew Salmonella typhimurium in 14C-labeled glucose to obtain 14C labeled endotoxin. Radiolabeled endotoxin was used to measure the rate of adsorption on activated charcoal. The rates of removal of endotoxin from normal saline, plasma, and whole blood will be presented in graphical form for use in design calculations. This work provides a foundation for encouraging in vivo hemoperfusion experimentation now underway at the University of Oklahoma and the Veteran's Administration Hospital in Oklahoma City.