Metabolic zonation in thioacetamide-induced liver cirrhosis.

After TAA administration to rats a central part may be distinguished histochemically from a marginal part in most of the cirrhotic nodules. The centre is characterized by a high glycogen content and by high activity of phosphorylase, G6Pase and SDH; the maxima of which are situated around the larger blood vessels. The vasculatory periphery, however, shows moderate G6PDH-activity. The marginal parts of the nodules are poor in glycogen and possess only weak G6Pase and phosphorylase activity, whereas high SDH- and G6PDH-activity can be demonstrated here. This distribution pattern leads to the conclusion that the larger blood vessels in the centre of the nodules are themselves the terminal afferent vessels. Thus the centre of the nodule corresponds to periportal zone 1, while G6PDH-activity marks the area corresponding to zone 3. The fact that the marginal parts of the nodules are marked by high SDH- but weak G6Pase-activity is interpreted as the result of a preferential arterial supply to this parenchymal part. The high G6PDH-activity of the marginal part is seen in context with the regeneration processes. In all animals single nodules could be found with a high glycogen content and extremely high G6PDH-activity. This loss of heterogeneity is interpreted as a first step in the direction of malignancy.