Corticotropin/beta-lipotropin biosynthesis, processing, and release in Nelson's syndrome.
Biosynthesis and processing of ACTH/beta-lipotropin was studied in Nelson's syndrome pituitary tumor tissue grown in monolayer culture. Radiolabeled peptides were immunoprecipitated and fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS/PAGE). Important findings include: 1) a virtual absence of 13K ACTH or 3.5K beta-endorphin production; 2) evidence indicating the presence of a 24-26K ACTH and beta-LPH containing intermediate (which implies a different order of processing from that reported in the mouse); 3) An extremely rapid rate of turnover and release of ACTH and beta-lipotropin (beta-LPH) similar to that of the mouse AtT20/D16v pituitary tumors. The latter finding is consistent with an intrinsic pituitary cell defect in the pathogenesis of this disorder.
D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D051379:Mice; D009347:Nelson Syndrome / Q000378:metabolism*; D010902:Pituitary Gland / Q000378:metabolism; D010911:Pituitary Neoplasms / Q000378:metabolism*; D013045:Species Specificity
D008077:Lipoproteins, LDL; D000324:Adrenocorticotropic Hormone