REGULATION OF RAT GLUCAGON RECEPTOR EXPRESSION

This report describes the isolation of a cDNA for the rat glucagon rec eptor by using the glucagon-like peptide 1 receptor cDNA as a probe. N orthern blot analysis using the cDNA clone showed that the message enc oding the receptor is approximately 2.3 kb in size and is expressed on ly in liver and kidney among seven tissues tested. To study how glucag on receptor expression is regulated in vivo. the levels of hepatic glu cagon receptor mRNA were measured in diabetic mouse model, db/db and c ontrol (db/+) mice. Interestingly, the receptor mRNA levels were simil ar between diabetic and control mice. In contrast, the number of hepat ic glucagon receptors in diabetic mice measured by binding assays was significantly higher than that found in normal mice. These results sug gest that the major regulation in hepatic glucagon receptor expression in vivo is at the posttranscriptional level. (C) 1994 Academic Press, Inc.