Endotoxins are heat stable proteins (lipopolysaccharide) that form structural components of the wall of gram-negative bacteria. They are liberated on the cell’s lysis or when the microorganisms die. Endotoxins are pyrogens; which are fever-causing agents.
Endotoxins are categorized as LPS or lipopolysaccharides. They contain fatty acids and disaccharide phosphates. They also contain O antigen and core polysaccharides. Their endotoxin activity is caused by the lipid A portion of lipopolysaccharides. The lipid A component does not cause any harm to the tissues. However, the body’s immune system sees it as an indicator that there is a presence of harmful microorganisms. So, the body’s immune system will do its best to get rid of intruders. This is the immune system’s way of protecting the body.