Glucagon-related peptides in the human gastrointestinal mucosa.
We studied the chromatographic profile and the distribution of glucagon-related peptides in the human gastrointestinal mucosa, using radioimmunoassays directed against the glucagon 6-15 and 19-29 sequences, and against the glicentin sequences 15-30 and 61-69, and a radioreceptor assay for glucagon. Very small amounts of glucagon-related peptides were found in the gastric mucosa, whereas at least four different components could be identified in the distal intestine. One component (mean concentration 130 pmol/g ileal mucosa) is similar to porcine glicentin for size and C-terminal extension, but differs from the glucagon part of the molecule in the N-terminal extension. A second component (mean concentration 131 pmol/g) is probably identical to porcine peak II enteroglucagon (glicentin 33-69), and a third component (7.9 pmol/g) seems to be identical with glucagon. A fourth component containing the glucagon sequence plus an N-terminal extension was also identified (1.7 pmol/g). Thus the human intestinal mucosa contains large amounts of peptides containing the glucagon sequence; at least one of these probably also possesses glucagon-like bioactivity. The proposed structures of the four components are consistent with the base sequence of the first half of the human glucagon gene.
D005753:Gastric Mucosa / Q000032:analysis*; D005768:Gastrointestinal Hormones / Q000032:analysis*; D005934:Glucagon / Q000032:analysis* / Q000276:immunology; D004763:Glucagon-Like Peptides / Q000032:analysis*; D006801:Humans; D007413:Intestinal Mucosa / Q000032:analysis*; D010455:Peptides / Q000032:analysis*; D052336:Proglucagon; D011498:Protein Precursors / Q000032:analysis; D011863:Radioimmunoassay; D011869:Radioligand Assay
D005768:Gastrointestinal Hormones; D010455:Peptides; D011498:Protein Precursors; D052336:Proglucagon; D004763:Glucagon-Like Peptides; C015236:glucagon-like-immunoreactivity; D005934:Glucagon