Dolichols and proliferating systems.

Abstract

The results obtained on dolichol metabolism, in two in vivo model systems, the developing rat liver and the regenerating rat liver, which provide different timing and interplay of proliferation and differentiation processes, have been reported. The regenerating liver presents a marked increase of both synthesis and content of dolichol, a decreased cholesterol/dolichol ratio, unchanged synthesis and content of dolichyl phosphate, or dolichol-kinase and dolichyl phosphate-phosphatase activities; no significantly modified distribution of dolichol homologs, with respect to the control. Total content of dolichols is growing during perinatal development. At fetal stages only short chain dolichols are detectable, while the content of dolichyl phosphate is very low and the activity of dolichyl phosphate-phosphatase is high. The study of the role of liver in dolichol supply to the body in the partially hepatectomized rat shows an increased content of dolichol in the blood; blood dolichol is essentially provided by the release from liver and dolichol traffic in the blood is mediated by multiple carriers.