In vivo and in vitro studies of bacterial endotoxin-membrane interactions and the effects of membrane-active agents

摘要: Abstract The characteristics of 51Cr-labelled E. coli endotoxin binding to human erythrocyte membranes in vitro have been investigated. A saturable component was apparent at low concentrations (less than 50 micrograms ml-1) relevant its vivo actions, while higher non-saturable and increased linear fashion. Experiments examining the ability unlabelled antagonize labelled toxin provided further evidence for these specific non-specific modes endotoxin-membrane interaction. Membrane-active agents previously shown reduce toxicity decreased vitro, with propranolol pranolium being most effective this regard. Tissue distribution studies following administration radiolabelled guinea-pigs showed a positive correlation between accumulation 51Cr-endotoxin lung elevations plasma acid phosphatase activity, measure toxicity. The guinea-pig reduced by prior treatment (+)-propranolol or pranolium, paralleling results studies. Our suggest that membrane-active such as may be useful adjuncts antimicrobial drugs therapy gram-negative endotoxaemia.