Both glucagon and glucagon-like peptide-1 (GLP-1) play an important role in the regulation
of nutrient homeostasis. In this study, the tissue distributions of the expression
of receptor genes for glucagon and GLP-1 were examined. Expression of glucagon receptor
gene was detected in liver, kidney, ileum and pancreatic islets but not in brain.
In contrast, expression of GLP-1 receptor gene was detected in brain, pancreas and
pancreatic islets but not in liver, kidney, or ileum. To investigate the existence
and characteristics of glucagon and GLP-1 receptors on pancreatic β cells, expression
of the receptor genes and translational regulation of the expression of the receptor
genes by glucose were analyzed in a mouse pancreatic β cell line, MIN6 cells. In the
cDNA pool of MIN6 cells, both glucagon and GLP-1 receptor genes were identified and
showed higher expression level in MIN6 cells cultured under high glucose condition
than in those cultured under low glucose condition. These results suggest that glucagon
and GLP-1 receptor genes are expressed in pancreatic β cells and their expression
is upregulated by glucose.
Key words
Tissue Distribution - Glucagon Receptor Gene - GLP-1 Receptor Gene - Mouse Insulinoma
Cell Line - Regulation by Glucose
