endotoxin en·do·tox·in (ěn'dō-tŏk'sən)
A toxin that forms an integral part of the cell wall of certain bacteria and is only released upon destruction of the bacterial cell. Endotoxins are less potent and less specific than most exotoxins and do not form toxoids. Also called intracellular toxin.
toxic substance bound to the bacterial cell wall and released when the bacterium ruptures or disintegrates. Endotoxins consist of lipopolysaccharide and lipoprotein complexes. The protein component determines its foreign (antigenic) nature; the polysaccharide component determines the antibody type that can react with the endotoxin molecule to produce an immune reaction. Endotoxins are rarely fatal, although they often cause fever.
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