Adrenocorticotropin-like and alpha-melanotropin-like peptides in a subpopulation of human gastrin cell granules: bioassay, immunoassay, and immunocytochemical evidence.
Adrenocorticotropin (ACTH)-like and alpha-melanotropin (alpha-MSH)-like peptides have been localized to a subpopulation of cytoplasmic (secretory) granules of human antropyloric gastric cells and of fetal and neoplastic gastrin cells. These granules also store gastrin and belong to the electron-dense variety of gastrin cell granules. Gastrin cells also contain granules of low to medium electron density; these store only gastrin and do not react with ACTH or alpha-MSH antisera. The alpha-MSH immunoreactive peptide was shown also to display alpha-MSH bioactivity by a combined immunosorbent-bioassay technique. This peptide cochromatographs with synthetic alpha-MSH in several systems and is not detected in oxyntic mucosa or in gastric muscle wall. As in the pituitary intermediate lobe, the alpha-MSH-like peptide may be formed by cleavage of ACTH-like peptides also in gastrin cells. These data provide additional evidence for local formation of ACTH/alpha-MSH-related peptides in gastrin cells and suggest a heterogenous peptide make-up of endocrine cell granules.
D000324:Adrenocorticotropic Hormone; D001681:Biological Assay; D003594:Cytoplasmic Granules / Q000648:ultrastructure*; D005455:Fluorescent Antibody Technique; D005753:Gastric Mucosa / Q000166:cytology*; D005755:Gastrins / Q000032:analysis / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D009074:Melanocyte-Stimulating Hormones; D008854:Microscopy, Electron; D010455:Peptides / Q000032:analysis*; D013270:Stomach / Q000166:cytology*; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology*
D005755:Gastrins; D010455:Peptides; D000324:Adrenocorticotropic Hormone; D009074:Melanocyte-Stimulating Hormones