Immunocytochemical study of the hypophysis in 25 dogs with pituitary-dependent hyperadrenocorticism.
Pituitary adenomas were found in 21 (84%) of 25 dogs with spontaneous pituitary-dependent hyperadrenocorticism. Six dogs had pars intermedia adenomas, whereas 15 had tumours of the pars distalis. Diffuse corticotroph cell hyperplasia was found in 1 of the 4 pituitaries without adenoma; in 2 dogs with pituitary adenoma, coexisting hyperplasia of the surrounding corticotrophs was also present. Immunocytochemical staining of the pituitaries revealed positive staining for ACTH, beta-lipotrophin, and beta-endorphin in the majority of both pars distalis and pars intermedia adenomas. The most frequent and intense staining was found with anti-beta-endorphin. In most part intermedia tumours, many cells stained strongly for alpha-MSH; double immunostaining of one pars intermedia adenoma for ACTH and alpha-MSH showed that some tumour cells stained only for ACTH or alpha-MSH whereas others contained both peptides. Only occasional cells stained for alpha-MSH in pars distalis adenomas.
D000236:Adenoma / Q000378:metabolism* / Q000473:pathology; D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000818:Animals; D003480:Cushing Syndrome / Q000378:metabolism / Q000473:pathology; D004285:Dogs; D004723:Endorphins / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D006965:Hyperplasia; D008297:Male; D009074:Melanocyte-Stimulating Hormones / Q000378:metabolism; D010902:Pituitary Gland / Q000378:metabolism* / Q000473:pathology; D010911:Pituitary Neoplasms / Q000378:metabolism* / Q000473:pathology; D001615:beta-Endorphin; D008083:beta-Lipotropin / Q000378:metabolism
D004723:Endorphins; D001615:beta-Endorphin; D000324:Adrenocorticotropic Hormone; D009074:Melanocyte-Stimulating Hormones; D008083:beta-Lipotropin