Transient expression of c-fos and constant expression of c-myc in freshly isolated and cultured normal adult rat hepatocytes.

A rapid and transient induction of the c-fos transcript followed 4 hr later by long-term increase in the c-myc transcript was observed after disruption of the liver tissue with collagenase or EDTA perfusion and after in vitro detachment of the cell-sheet of liver cells in culture. This increase of c-fos and c-myc transcripts could result from both an increased gene transcription and a stabilization of the corresponding mRNAs, as suggested by the effects of cycloheximide and actinomycin D. This increase was dependent on the extent of cell dissociation and isolation and was not the effect of dissociating agents.

Early reversible nuclear alterations induced by sodium butyrate in cultured hepatoma cells.

Exposure of HTC cells to sodium butyrate caused various cellular and subcellular changes. A high proportion of the cells became elongated or spherical after 48 h. Already after 1-4 h, nucleoli appeared modified as shown by changes in the distribution of their components.

Immunolocalization of fetal aldolase isoenzymes in rat regenerating liver after carbon tetrachloride intoxication.

Light and electron microscopic immunolocalization of adult and fetal aldolase isoenzymes has been studied in rat liver 72 h after CCL4 intoxication. As in rat regenerating liver after partial hepatectomy, fetal aldolases A and C were located in sinusoidal cells (Kupffer and endothelial cells) whereas adult aldolase B was present in hepatocytes only. Our results are different from those obtained with fetal and cancerous livers; they suggest that control mechanisms of gene regulation different in liver regeneration and in cancer.