ACTH is generated in the pituitary gland by the proteolytic processing of a polypeptide
precursor proopiomelanocortin (POMC). Other POMC-derived peptides, such as the N-
terminal fragment, the joining peptide, β-lipotropin, γ-lipotropin, and β-endorphin, are
consecrated with ACTH by exocytosis on an equimolar basis. All of these peptides have
been measured in blood by radioimmunoassay or immunoradiometricassay, and their levels
are markers of the overall coricotroph function. The normal ratio between the various …