Prolactin receptor expression in lymphocytes from patients with hyperprolactinemia or acromegaly.
Previous reports demonstrated that prolactin receptors (PRL-R) are widely expressed on cells of the immune system. We analyzed a possible regulation of PRL-R expression on human mononucleated blood cells by prolactin (PRL) itself. PRL-R expression was analyzed by immunofluorescence on T and B lymphocytes and monocytes from peripheral blood mononucleated cells (PBMC) of patients with hyperprolactinemia or acromegaly compared with sex- and age-matched control subjects. The frequency of PRL-R positive cells and the intensity of PRL-R expression was only modified among the CD8+ T cell population of hyperprolactinemic patients with macroadenoma. No correlation was reported between PRL-R expression and circulating PRL levels. The percentage of PRL-R+ cells on B or T lymphocytes and monocytes as well as the capacity of PBMC to proliferate in response to T cell mitogens were not significantly different in bromocriptine-treated compared with untreated patients. These findings suggest that factors other than pituitary PRL play the major role in regulating PRL-R expression on cells of the immune system.
D000172:Acromegaly / Q000188:drug therapy / Q000378:metabolism*; D000236:Adenoma / Q000276:immunology / Q000378:metabolism; D000328:Adult; D001971:Bromocriptine / Q000627:therapeutic use; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism / Q000473:pathology; D002478:Cells, Cultured; D015536:Down-Regulation; D005434:Flow Cytometry; D006801:Humans; D006966:Hyperprolactinemia / Q000188:drug therapy / Q000276:immunology / Q000378:metabolism*; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000378:metabolism*; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000276:immunology / Q000378:metabolism; D011981:Receptors, Prolactin / Q000187:drug effects / Q000378:metabolism*
D011981:Receptors, Prolactin; D001971:Bromocriptine