Periportal localization of glucagon receptor mRNA in rat liver and regulation of its expression by glucose and oxygen in hepatocyte cultures.

Glucagon is the major hormone activating glycogenolysis and gluconeogenesis both localized in the periportal, more aerobic zone of the liver. Accordingly, the glucagon receptor (GcgR) mRNA was found to be predominantly expressed in this area. In hepatocyte cultures high glucose concentrations as reached after a meal induced GcgR mRNA under arterial but not venous pO2. The induction by glucose was partially antagonized by insulin and unaffected by glucagon. The modulation by 02 of the glucose-dependent induction would contribute to the zonated expression of GcgR mRNA.