Potential targets for glucagon-like peptide 2 (GLP-2) in the rat: distribution and binding of i.v. injected (125)I-GLP-2.
Glucagon-like peptide 2 (GLP-2) is a 33-amino acid (1-33) intestinotrophic peptide. In this study, the distribution and binding of i.v. injected radiolabeled GLP-2 (1-33) were investigated in rats using autoradiography in order to target possible binding sites. The major part of (125)I-GLP-2 (1-33) was distributed to kidneys, liver, and the gastrointestinal tract. In the small intestine, a high density of grains was localized in the epithelium with a predominance in the luminal part of the villus. The saturability of (125)I-GLP-2 (1-33) was investigated by administration of excess amounts of non-radioactive GLP-2 (1-33) or the primary metabolite of GLP-2 degradation, GLP-2 (3-33). In the small intestine, (125)I-GLP-2 was displaced both by non-radioactive GLP-2 (1-33) and (3-33), suggesting that the uptake of GLP-2 (1-33) in the small intestine is receptor-specific and that the metabolite GLP-2 (3-33) may interact with the GLP-2 receptor.
Thulesen
J
J
Department of Medical Anatomy, University of Copenhagen, The Panum Institute, 2200 N, Copenhagen, Denmark. J.Thulesen@mai.ku.dk
Hartmann
B
B
Orskov
C
C
Jeppesen
P B
PB
Holst
J J
JJ
Poulsen
S S
SS
D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive; D004848:Epithelium / Q000378:metabolism; D005260:Female; D053767:Glucagon-Like Peptide 2; D000067757:Glucagon-Like Peptide-1 Receptor; D004763:Glucagon-Like Peptides; D007275:Injections, Intravenous; D007421:Intestine, Small / Q000378:metabolism; D007457:Iodine Radioisotopes; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D010455:Peptides / Q000097:blood / Q000378:metabolism* / Q000493:pharmacokinetics; D011485:Protein Binding; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D018027:Receptors, Glucagon / Q000032:analysis / Q000378:metabolism*; D013379:Substrate Specificity
C000593835:Glp1r protein, rat; D053767:Glucagon-Like Peptide 2; D000067757:Glucagon-Like Peptide-1 Receptor; D007457:Iodine Radioisotopes; D010455:Peptides; D018027:Receptors, Glucagon; D004763:Glucagon-Like Peptides