Glucocorticoid receptor expression in nontumorous human pituitaries and pituitary adenomas |
| |
Authors: | Dr Kalman Kovacs MD PhD Fabio Rotondo Lucia Stefaneanu PhD Forouzandeh Fereidooni MD Eva Horvath PhD Ricardo V Lloyd MD PhD Bernd W Scheithauer MD |
| |
Institution: | (1) Department of Laboratory Medicine, St. Michael’s Hospital, University of Toronto, Toronto;(2) Mayo Clinic, 55905 Rochester, MN, USA;(3) Division of Pathology, St. Michael’s Hospital, M5B1W8 Toronto, Canada |
| |
Abstract: | Glucocorticoids have multiple actions, including a suppressive feedback effect on pituitary corticotrophs via the glucocorticoid
receptor (GR). By immunocytochemistry, we studied GR expression in 86 surgically removed various pituitary adenoma types.
Ten cases contained nontumorous pituitary fragments, which were suitable for immunocytochemical investigation. In addition,
30 autopsy-obtained pituitaries, 10 of them containing incidental microadenomas, were examined as well. Using a polyclonal
GR antibody, the streptavidin-biotin-peroxidase complex method revealed nuclear and/or cytoplasmic GR immunoreactivity in
many nontumorous corticotrophs and other adenohypophysial cell types and in S-100 protein immunopositive stellate cells. Cellular
localization was confirmed by double immunostaining. Pars intermedia corticotrophs, posterior lobe axons, Herring bodies,
and pituicytes as well as several endothelial cells lining the capillaries were also immunopositive. GR immunoreactivity was
also demonstrated in many GH, PRL, ACTH, TSH, FSH, LH α-subunit producing adenomas, null cell adenomas, and oncocytomas. The
extent and degree of immunostaining varied considerably from case to case. Suppressed corticotrophs showing the Crooke’s hyaline
change due to glucocorticoid excess were present in the nontumorous pituitaries of patients with Cushing’s disease and in
those treated with pharmacologic doses of glucocorticoids. Many suppressed nontumorous corticotrophs exhibited only weak or
no GR immunopositivity, indicating GR downregulation accompanied by cellular injury. Study of autopsy obtained pituitaries
for GR yielded inconclusive results indicating that autopsy obtained adenohypophyses are not suitable for the immunocytochemical
investigation of GR. |
| |
Keywords: | Glucocorticoids histology immunocytochemistry pituitary pituitary tumor receptor |
本文献已被 SpringerLink 等数据库收录! |
|