title: Characterization of lipotropin-, corticotropin-, and beta-endorphin-immunoreactive materials secreted in vitro by a human pituitary adenoma responsible for a case of Nelson's syndrome.
abstract: A human pituitary adenoma responsible for a case of Nelson's syndrome was maintained in organ culture and the incubation medium was examined with four different RIAs; human corticotropin (ACTH), beta-MSH, lipotropin (LPH), and beta-endorphin (beta-End). All four immunoreactivites (IRs) were present in the medium obtained after 24 h of incubation. Gel exclusion chromatography under  denaturing conditions (6 m guanidine HCl) revealed several immunoreactive components. Two components having both human beta-MSH (beta-hMSH) and human LPH (hLPH) IR coeluted with beta-hLPH and gamma-hLPH; a component with beta-hMSH IR but no hLPH IR coeluted with [125I]beta-hMSH; a component with human ACTH (hACTH) IR eluted at the position of hACTH. Sephadex G-50 gel exclusion chromatography revealed that approximately 80% and 20% of human beta-End (beta-hEnd) IR were accounted for by components coeluting with beta-hLPH and beta-hEnd, respectively. These data demonstrate the presence in this incubation medium of materials similar to if not identical with beta-hLPH, gamma-hLPH, hACTH, beta-hMSH, and beta-hEnd; they suggest that all of these peptides may be secreted in the circulation of patients with Nelson's syndrome.
mesh_terms: D000236:Adenoma / Q000150:complications / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D004723:Endorphins / Q000378:metabolism*; D006801:Humans; D009347:Nelson Syndrome / Q000209:etiology / Q000503:physiopathology*; D010911:Pituitary Neoplasms / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology*; D011863:Radioimmunoassay; D008083:beta-Lipotropin / Q000378:metabolism*
chemical_list: D004723:Endorphins; D000324:Adrenocorticotropic Hormone; D008083:beta-Lipotropin