The effect of danazol on the production of C1 inhibitor in the guinea pig.

The production of C1 inhibitor (C1-INH) in guinea pig liver was studied following administration of danazol. Immunochemical assays of the inhibitor were performed on serial serum specimens. An increase in serum C1-INH was observed following danazol treatment. Immunohistochemical studies confirmed that the liver is the sole site of synthesis of C1-INH in guinea pigs. This appears to occur in certain clones of hepatocytes. Ultrastructural studies revealed an increase in coarse endoplasmic reticulum and mitochondria in danazol-treated animals. In in vitro studies with liver slices, however, more C1-INH was detected in culture supernatants from untreated animals than from danazol-treated animals. This observation suggests that secretion of C1-INH from stimulated hepatocytes may require additional factors which are present in vivo but not in vitro.