Abstract
Liver regeneration has served as an important in vivo model for studying the control of differentiation. The molecular mechanisms responsible for the negative regulation of the albumin promoter during regeneration have not been examined previously. Changes in the proteins interacting with the albumin promoter were characterized using nuclear extracts prepared from the livers of rats undergoing chemically induced regeneration. Reduction in the activities of both hepatocyte nuclear factor-1 (HNF-1) and factors binding to the D site are responsible for the loss of albumin transcription during regeneration. No evidence for the involvement of a transcriptional repressor in this process was found.