Acute phase reactants enhance CCl4 induced liver cirrhosis in the rat.

High levels of acute phase proteins (acute phase reactants, APR) suppress acute inflammatory reactions in the rat. As many APR have antiprotease properties, including an anticollagenase activity, the effect of APR on the development of CCl4-induced liver fibrosis was investigated in rats. APR were provoked by repeated injections of epinephrine, inducing a broad spectrum of APR. This reaction can be monitored measuring alpha 2-macroglobulin levels in the rat (alpha 2-macrofetoprotein, alpha M FP). This protein was found to inhibit both acute galactosamine hepatitis and acute CCl4-induced liver toxicity. The animals with high levels of APR at the start of CCl4 treatment developed a more severe degree of fibrosis and cirrhosis than the control group in which no acute phase reaction was induced. Epinephrine alone had no such effects. Additionally, the APR positive group showed an initially lower degree of hepatocellular damage when compared to control animals. This uncoupling of liver cell damage and subsequent fibrosis may demonstrate that higher levels of APR might be important as to the development of cirrhosis, possibly based on the anticollagenase activity of these proteins.