Liver metabolic zonation in rat biliary cirrhosis: distribution is reverse of that in toxic cirrhosis.

Liver cell functional heterogeneity has been shown to persist in toxic CCl4 cirrhosis in growing rats, but the zonation observed in cirrhotic nodules may be different in other types of cirrhosis. To investigate this possibility, we looked at the zonal activities of two microsomal enzymes, glucose-6-phosphatase and NADPH dehydrogenase, in cirrhotic nodules from growing rats with chronic cholestasis. Zonal activities were measured by quantitative cytochemistry and microdensitometry. Liver cell heterogeneity was demonstrated, and we confirmed that the metabolic zonation is the mirror image of that observed in toxic cirrhosis, with periportal activity at the nodule periphery and perivenular activity at the nodule centers. Glucose-6-phosphatase activity was 2.06 times higher at the peripheries of the nodules than at the centers, whereas NADPH dehydrogenase activity at the nodule periphery was 72% of the nodule center activity. We conclude that a liver cell functional heterogeneity persists in biliary rat cirrhosis, with zonation the reverse of that previously found in toxic CCl4 cirrhosis.