title: Correlative studies between the presence of thyrotropin-releasing hormone (TRH) receptors and the in vitro stimulation of growth-hormone (GH) secretion in human GH-secreting adenomas.
abstract: Specific receptors for TRH were characterized on cellular membranes of 6 out of 13 somatotrophic adenomas obtained from acromegalic patients. These receptors had the same dissociation constant (Kd: 62 +/- 10 nM) as those found in human PRL-secreting adenomas, but their maximal number of binding sites (Bmax: 76 +/- 24 fmol/mg of protein) was six fold smaller. A good correlation was found between the presence of TRH receptors and the in vitro TRH-induced stimulation of GH secretion. The increase in GH release varied from 25 to 200%. It was thus concluded that these receptors are functional. However, why only some of the human somatotrophic adenomas possess TRH receptors and respond to TRH in vitro needs further investigations.
authors.forename: M
authors.initials: M
authors.lastname: Le Dafniet
authors.forename: P
authors.initials: P
authors.lastname: Garnier
authors.forename: D
authors.initials: D
authors.lastname: Bression
authors.forename: A M
authors.initials: AM
authors.lastname: Brandi
authors.forename: J
authors.initials: J
authors.lastname: Racadot
authors.forename: F
authors.initials: F
authors.lastname: Peillon
mesh_terms: D000236:Adenoma / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D013006:Growth Hormone / Q000378:metabolism*; D006801:Humans; D010911:Pituitary Neoplasms / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018025:Receptors, Thyrotropin-Releasing Hormone; D013004:Somatostatin / Q000378:metabolism; D013973:Thyrotropin-Releasing Hormone / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D011956:Receptors, Cell Surface; D018025:Receptors, Thyrotropin-Releasing Hormone; D007987:Gonadotropin-Releasing Hormone; D013004:Somatostatin; D005680:gamma-Aminobutyric Acid; D013973:Thyrotropin-Releasing Hormone; D013006:Growth Hormone