Distribution of gastrin-releasing peptide (GRP)-like immunoreactivity in the rat.
Rat tissues were examined for gastrin-releasing peptide (GRP)-like immunoreactivity, using carboxy-terminus-specific antibody made against GRP (19-27), which is thought to be the biologically active site and to be common among species. The distribution of GRP-like immunoreactivity in the rat was similar to that of bombesin-like immunoreactivity. Sephadex G 50 chromatography revealed two peaks of GRP-like reactivity in the rat stomach. Immunohistochemical studies using the antiserum to GRP (19-27) revealed numerous nerve fibers in the mucosa of the rat stomach. In the antral mucosa, GRP-containing nerves were present mainly around the base of the antral glands. Some GRP-containing nerves were in contact with gastrin-containing cells and somatostatin-containing cells. GRP-containing nerve fibers were numerous in the middle portion of the oxyntic gland, where somatostatin-containing cells were also detected. None of the endocrine cells stained positively with anti-GRP serum. These results support the hypothesis that GRP is a neurotransmitter in the stomach and that the peptide plays a physiological role in the gastrointestinal tract.
D000818:Animals; D005753:Gastric Mucosa / Q000378:metabolism*; D019886:Gastrin-Releasing Peptide; D005755:Gastrins / Q000378:metabolism; D007120:Immunochemistry; D008297:Male; D010455:Peptides / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000378:metabolism; D014018:Tissue Distribution
D005755:Gastrins; D010455:Peptides; D013004:Somatostatin; D019886:Gastrin-Releasing Peptide