Tissue distribution of rat glucagon receptor and GLP-1 receptor gene expression.
The regulation of glucose metabolism by glucagon and GLP-1 is well established, but novel functions for these and other proglucagon-derived peptides are less well defined. This paper highlights the diversity of both GLP-1 and glucagon activity by studying the tissue distribution of glucagon and GLP-1 receptor gene expression by both Southern blot analysis of RT-PCR products and nuclease protection assays. By Southern blot analysis of RT-PCR products, GLP-1 receptor mRNA was detected in lung, hypothalamus, hippocampus, cerebral cortex, kidney, pancreas, and throughout the gastrointestinal tract. Glucagon receptor expression was detected in liver, kidney, spleen, thymus, adrenal glands, pancreas, cerebral cortex, lung, and throughout the gastrointestinal tract. Nuclease protection assay revealed glucagon receptor expression to be highest in liver and kidney, whereas GLP-1 receptor expression was only detected by protection assay in lung, stomach, and large bowel. Despite previous evidence that other receptors for proglucagon-derived peptides may exist, no evidence of novel receptors or multiple isoforms of the glucagon and GLP-1 receptors was found, indicating that the two cloned receptors may mediate all the effects of proglucagon-derived peptides, or that novel receptors may share less homology with the glucagon and GLP-1 receptors than previously anticipated.
Dunphy
J L
JL
Prince Henry's Institute of Medical Research and Monash University, Department of Medicine, Monash Medical Centre, Clayton, Victoria, Australia.
Taylor
R G
RG
Fuller
P J
PJ
D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D017931:DNA Primers; D015342:DNA Probes; D000067757:Glucagon-Like Peptide-1 Receptor; D009693:Nucleic Acid Hybridization; D009928:Organ Specificity; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D018027:Receptors, Glucagon / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012689:Sequence Homology, Nucleic Acid; D015719:Single-Strand Specific DNA and RNA Endonucleases
D017931:DNA Primers; D015342:DNA Probes; C000593835:Glp1r protein, rat; D000067757:Glucagon-Like Peptide-1 Receptor; D012333:RNA, Messenger; D018027:Receptors, Glucagon; D015719:Single-Strand Specific DNA and RNA Endonucleases