Transcriptional activity of the phosphoenolpyruvate carboxykinase gene decreases in regenerating rat liver.

Rat cytosolic phosphoenolpyruvate carboxykinase (PEPCK) gene expression and enzyme activity in liver were studied in rats fasted for 12 hours before and after partial hepatectomy, sham operation or no operation. Transcriptional activity and mRNA levels decreased in regenerating liver compared to sham-operated and unoperated controls. In contrast, PEPCK enzyme activity in regenerating liver was similar to that in the livers of sham-operated and unoperated controls. Since all the animals were fasted the decrease in transcription is probably caused by some factor other than insulin, the known repressor of PEPCK gene expression.