Potential targets for glucagon-like peptide 2 (GLP-2) in the rat: distribution and binding of i.v. injected I-125-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 radio labeled GLP-2 (1-33) were investigated in rats using autoradiography in ord er to target possible binding sites. The major part of I-125-GLP-2 (1-33) w as distributed to kidneys, liver, and the gastrointestinal tract. In the sm all intestine, a high density of grains was localized in the epithelium wit h a predominance in the luminal part of the villus. The saturability of I-1 25-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, G LP-2 (3-33). In the small intestine, I-125-GLP-2 was displaced both by non- radioactive GLP-2 (1-33) acid (3-33), suggesting that the uptake of GLP-2 ( 1-33) in the small intestine is receptor-specific and that the metabolite G LP-2 (3-33) may interact with the GLP-2 receptor. (C) 2000 Elsevier Science Inc. All rights reserved.