Control of Liver Deoxyribonucleic Acid Synthesis

There is strong evidence that the stimulus to liver regeneration after partial hepatectomy residues in circulating molecules whose concentrations in the blood rise after the operation. To learn about the stimulatory molecules, efforts have been made to induce with chemicals the synthesis of DNA and the multiplication of cells in the intact liver.An infusate has been devised that stimulates DNA synthesis in the liver of the unoperated rat about half as well as 70% hepatectomy. The infusate, comprised of L-triiodothyronine, amino acids, glucagons, and heparin, appears to act, at least in part, by providing the liver with increased amounts of fatty and amino acids. Several pieces of evidence are given to rule out the possibility that the infusate acts to induce DNA replication by damaging liver cells.The question is raised whether the psoriatic lesion is the result of changes in the epithelial cells themselves or, in analogy with the parenchymal liver cell, in the levels of some of the components of the fluid that nourishes the cells