Effect of bacterial endotoxin on plasma concentration of haptoglobin and fibrinogen in rats treated with metopyrone.

During the acute phase of the inflammatory process there is a characteristic increase in some plasma proteins called collectively acute phase reactants (APR) as well as in the levels of corticosteroids. A bacterial endotoxin (LPS) that induces a strong acute phase response, indicated by high levels of fibrinogen and haptoglobin, did not show this effect when administered to rats treated previously with metopyrone, a specific inhibitor of corticosteroid hormone synthesis. These results suggest that adequate levels of these hormones are important for the production of acute phase reactants.