title: Gastrin releasing peptide (GRP) is present in a GRP(1-27) form in anterior pituitary cells of the guinea pig.
abstract: Immunohistochemical and chromatographic studies were performed on the guinea pig anterior pituitary gland with an antiserum recognizing an epitope within the gastrin releasing peptide (GRP) carboxyterminal amino acid sequence Val-Gly-His-Leu-Met-NH2. Within the anterior pituitary gland GRP-like immunoreactive cells were identified. The GRP-like immunoreactive cells were distributed heterogenously in the gland, predominantly located in ventral aspects of the anterior pituitary. Intracellularly, the immunoreactivity elements were identified as granula-like structures in the cytoplasma. To further characterize the peptide displaying GRP-like immunoreactivity within the pituitary cells, the GRP-like substances were analyzed by radioimmunoassay and gel filtration chromatography. Using this analytical approach it was determined that the guinea pig pituitary extract contained a peptide with characteristics similar to that of authentic porcine GRP(1-27). Only trace amounts of smaller C-terminal fragments were identified. These results indicate, in contrast to findings in other tissues, the GRP(1-27) is not further degraded into smaller peptide fragments.
authors.affiliation: Department B, University of Copenhagen, Denmark.
authors.forename: P J
authors.initials: PJ
authors.lastname: Larsen
authors.forename: M M
authors.initials: MM
authors.lastname: O'Hare
authors.forename: A
authors.initials: A
authors.lastname: Vangsted
authors.forename: J D
authors.initials: JD
authors.lastname: Mikkelsen
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D019886:Gastrin-Releasing Peptide; D006168:Guinea Pigs; D007150:Immunohistochemistry; D008297:Male; D010455:Peptides / Q000032:analysis*; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism*; D011863:Radioimmunoassay
chemical_list: D010455:Peptides; D019886:Gastrin-Releasing Peptide