HMP-shunt and cholesterol metabolism in experimental models involving normal and preneoplastic liver growth.

Previous studies from our laboratories have shown a stimulation of HMP-shunt, cholesterol metabolism and DNA synthesis during cell proliferation. In order to understand the co-ordinated regulation of these pathways during cell growth, the above metabolic pathways were studied in: liver regeneration after partial hepatectomy, lead-induced liver hyperplasia, liver cell proliferation induced by insulin in streptozotocin-diabetic rats, liver cell proliferation in fasted rats after refeeding and, hepatocyte nodules induced by a selection procedure. The results indeed indicate that changes in HMP-shunt and cholesterol metabolism occur at a very early stage during the process of normal as well as preneoplastic cell growth. The coordinated regulation between cell growth and changes in these metabolic pathways needs further study.