Zonation of metabolism and gene expression in liver

ConclusionThe zonation of gene expression resulting in the different cellular equipment of liver cells with enzymes, translocators and subcellular structures is regulated mainly at a pretranslational level. In the dynamic zonation of carbohydrate metabolizing enzymes, gradients in oxygen and in the glucagon/insulin ratio decreasing from the periportal to the perivenous area appear to be major effectors. In the stable zonation of ammonia-metabolizing enzymes local paracrine cell-cell interactions via diffusible mediators could play a major role (Fig. 6).