Endotoxin is lipopolysaccharide (LPS) a component of the other membrane of most gram negative bacteria. Administration of endotoxin results in the systemic inflammatory response syndrome and subsequent multiple organ failure.
LPS directly induces upregulation of integrins on leucocytes and expression of P and E selectins and ICAM-1 on endothelial cells. This enhances leucocyte - endothelial cell interactions with adhesion and transmigration. LPS also induces secretion of free oxygen radicals and pro-inflammatory cytokines (IL-1 and TNF-).
Endotoxic shock is a lethal inflammatory state mediated by TNF- and IL-1. Mice may be protected from endotoxic shock by IL-10.