Amidated joining peptide in the human pituitary, gut, adrenal gland and bronchial carcinoids. Immunocytochemical and immunochemical evidence.
The distribution of the proopiomelanocortin-derivated amidated joining peptide (JP-N) was examined in the human pituitary gland, adrenal gland, gut and in three bronchial carcinoids. Double immunostaining showed coexistence of immunoreactive JP-N and other proopiomelanocortin derivatives, e.g., ACTH, beta-endorphin, Pro-tau-MSH, in the pituitary gland and adrenal medulla. The JP-N immunoreactive cells in the adrenal medulla were identified as a subpopulation of adrenaline-producing cells by means of an antiserum against phenylethanolamine N-methyltransferase. In the gut immunoreactive JP-N was costored with somatostatin in endocrine cells. Using radioimmunoassay, JP-N was found in higher concentrations than ACTH and alpha-MSH in the gut but not in the adrenal gland. Gel chromatography of gastric antrum and adrenal gland extracts showed three and two dominating components of immunoreactive JP-N, respectively, but under reduced conditions most of the immunoreactive material appeared as of low molecular weight in both extracts. In conclusion, immunoreactive JP-N is a major product from the processing of proopiomelanocortin in human extrapituitary tissues. The molecular forms of immunoreactive JP-N correspond to previous findings in the human pituitary gland.
Department of Medical Cell Research, Lund, Sweden.
A
A
Bjartell
M
M
Fenger
R
R
Ekman
F
F
Sundler
D000311:Adrenal Glands / Q000378:metabolism*; D000595:Amino Acid Sequence; D001984:Bronchial Neoplasms / Q000032:analysis*; D002276:Carcinoid Tumor / Q000032:analysis*; D002850:Chromatography, Gel; D004064:Digestive System / Q000032:analysis*; D005455:Fluorescent Antibody Technique; D006801:Humans; D007120:Immunochemistry; D007124:Immunoenzyme Techniques; D008969:Molecular Sequence Data; D010446:Peptide Fragments; D010902:Pituitary Gland / Q000032:analysis*; D011333:Pro-Opiomelanocortin; D011863:Radioimmunoassay
D010446:Peptide Fragments; D011333:Pro-Opiomelanocortin; C064114:pro-opiomelanocortin joining peptide(79-108)