Effects of hepatic enzyme inducers and mitogens on experimental Tyzzer's disease in rats.

We studied the effects of chemicals which induce liver enlargement and can induce hepatic protein synthesis on experimental Tyzzer's disease in rats. Plasma transaminase values were evaluated as an indicator of the severity of the disease. Chemicals used were phenobarbital sodium and 3-methylcholanthrene as hepatic enzyme inducers, and lead nitrate and ethylene dibromide as mitogens of hepatocytes. In rats non infected with Tyzzer's organism, liver weight in those treated with these chemicals was higher than that in rats without chemical treatment. Tyzzer's disease-infected rats treated with these chemicals showed higher plasma transaminase values and more severe histopathologic liver lesions than infected rats without chemical treatment. The results indicated that the growth of Tyzzer's organisms in hepatocytes was accelerated in the course of hepatocytic metabolic changes during liver enlargement, and that protein synthesized in the hepatocyte may play an important role in the nutritive requirements of the organism.