title: Effects of thyrotropin-releasing hormone and gonadotropin-releasing hormone on inositol phospholipid turnover in endocrinologically inactive pituitary adenomas and prolactinomas.
abstract: We examined the effects of GnRH and TRH on inositol phospholipid turnover in 11 endocrinologically inactive pituitary adenomas and 5 prolactinomas. In 9 of the 11 nonsecreting adenomas, GnRH induced a significant increase in inositol phospholipid turnover; of those that responded, increased inositol phospholipid turnover in response to TRH occurred in 6. Neither of the 2 prolactinomas exposed to GnRH responded to GnRH, whereas all 5 prolactinomas responded to TRH. These findings demonstrate the presence of functional GnRH receptors on endocrinologically inactive pituitary adenomas. The phosphatidyl inositol-linked receptor status of these tumors differs from that of prolactinomas. These receptors may offer a possible target for therapeutic intervention in endocrinologically inactive adenomas.
authors.affiliation: Department of Medicine, Charing Cross and Westminster Hospital Medical School, London, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Levy
authors.forename: S L
authors.initials: SL
authors.lastname: Lightman
mesh_terms: D000236:Adenoma / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000818:Animals; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D008297:Male; D008875:Middle Aged; D009693:Nucleic Acid Hybridization; D010716:Phosphatidylinositols / Q000378:metabolism*; D010906:Pituitary Hormone-Releasing Hormones / Q000494:pharmacology*; D010911:Pituitary Neoplasms / Q000378:metabolism*; D015175:Prolactinoma / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D011966:Receptors, LHRH / Q000032:analysis; D015290:Second Messenger Systems; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D010716:Phosphatidylinositols; D010906:Pituitary Hormone-Releasing Hormones; D012333:RNA, Messenger; D011966:Receptors, LHRH; D013973:Thyrotropin-Releasing Hormone