Hepatic blood supply and control of deoxyribonucleic acid synthesis in liver

Abstract

Permanent ligation of the branch of the hepatic portal vein supplying a portion (67%) of the liver causes, in the nonligated lobes, increases in the rate of RNA synthesis, in the electrophoretic mobility of the nuclei, and in DNA formation that are indistinguishable from those that follow partial hepatectomy. Temporary ligation of the branch vessel causes some or all of these changes in the nonligated lobes depending on the length of the ligation time. Thus, a ligation period of 0.5–2 min produces the alterations in RNA formation and in the nuclear membrane, but hepatic DNA synthesis is unaffected. Ligation of the branch vessel for 10 min yields, in addition, a marked increase in DNA formation. The possibility is considered that the changes in RNA synthesis and in the nuclear membrane result directly from the vascular disturbance caused by partial hepatectomy or the ligation of the portal vein branch. At least some of the alterations required to stimulate DNA formation, however, appear to have a different etiology, possibly related to a loss of liver function.