Mechanism of Endotoxin Interaction with Human Leucocytes

Abstract

An investigation to define the mechanism of the interaction between endotoxin and human leucocytes is reported. Endotoxin produces the following changes in human leucocytes suspended in vitro in normal plasma or serum: leak of kininase and lysozyme from the cell into the medium, decreased cellular α‐glucosidase and phosphorylase activity, increased production of lactate and of ¹⁴CO₂ from glucose‐1‐¹⁴C and increased incorporation of tritiated uridine into RNA and acid‐soluble nucleotide. The metabolic changes induced by endotoxin and the uptake of radioactive endotoxin by granulocytes are diminished if the suspending medium is depleted of complement components.The thesis is presented that endotoxin in the presence of complement is ingested by or adheres to the human granulocyte and induces a series of metabolic changes resembling those associated with phagocytosis.