An immunoperoxidase study of a human pituitary adenoma associated with Cushing's syndrome.
A large endocrine active pituitary adenoma causing a Cushing's syndrome was investigated for the presence of subunits of the corticotropin-lipotropin precursor by immunohistology. A quantitative study revealed immunoreactivity (ir) for ACTH in 87.1% of the adenoma cells, beta-lipotropin-ir in 77.1%, beta-endorphin-ir in 75.3%, alpha-MSH-ir in 22.9% and methionine-enkephalin-ir in 7.8%. The adjacent distal pituitary gland showed a six-fold increase of prolactin-ir cells indicating the release of biologically active endogenous opiates. The strong alpha-MSH-ir within the adenoma cells in contrast to those of the distal pituitary may signify that alpha-MSH was being secreted by the adenoma. The proportions of other endocrine cell types within the anterior pituitary were normal (3.1% corticotrophs, 49.4% somatotrophs, 8.2% gonadotrophs and 7.1% thyrotrophs). 0.5% of the cells of the distal pituitary and 0.1% within the adenoma were VIP-ergic, which may be due to a vasoregularitory system and/or be involved in prolactin release.
D000236:Adenoma / Q000032:analysis / Q000150:complications / Q000473:pathology*; D000324:Adrenocorticotropic Hormone / Q000032:analysis*; D003480:Cushing Syndrome / Q000209:etiology*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008875:Middle Aged; D010908:Pituitary Hormones, Anterior / Q000032:analysis*; D010911:Pituitary Neoplasms / Q000032:analysis / Q000150:complications / Q000473:pathology*; D011333:Pro-Opiomelanocortin; D011498:Protein Precursors / Q000032:analysis*; D008083:beta-Lipotropin / Q000032:analysis*
D010908:Pituitary Hormones, Anterior; D011498:Protein Precursors; D011333:Pro-Opiomelanocortin; D000324:Adrenocorticotropic Hormone; D008083:beta-Lipotropin