title: Somatostatin receptors in human growth hormone and prolactin-secreting pituitary adenomas.
abstract: [125I-Tyr]Somatostatin [( 125I-Tyr]SRIH) binding was found in 11 GH-secreting pituitary adenomas [Kd = 0.46 +/- 0.15 (+/- SE) nM; maximum binding, 165 +/- 35 fmol/mg protein). This binding was specific, since it was displaced by somatostatin-14 (SRIH-14), N-Tyr-SRIH-14, and SRIH-28. In contrast, a number of peptides and drugs not structurally related to SRIH, such as bombesin, dopamine, LHRH, met-enkephalin, naloxone, neurotensin, secretin, substance P, TRH, or vasoactive intestinal peptide, did not affect [125I-Tyr]SRIH binding. [125I-Tyr]SRIH specific binding also was found in PRL-secreting pituitary adenomas. The kinetic characteristics of the specific binding were similar to those of GH-secreting adenomas. However, maximal binding was one quarter that of GH-secreting adenomas (37 +/- 9 fmol/mg protein). In contrast, nonsecreting (chromophobe) tumors were devoid of any specific binding. Finally, in acromegaly, the density of [125I-Tyr]SRIH-binding sites in the adenomas was negatively correlated with plasma GH levels before surgery (r = -0.80). This suggests that somatostatinergic control is involved in GH secretion in acromegalic patients.
authors.forename: E
authors.initials: E
authors.lastname: Moyse
authors.forename: M
authors.initials: M
authors.lastname: Le Dafniet
authors.forename: J
authors.initials: J
authors.lastname: Epelbaum
authors.forename: P
authors.initials: P
authors.lastname: Pagesy
authors.forename: F
authors.initials: F
authors.lastname: Peillon
authors.forename: C
authors.initials: C
authors.lastname: Kordon
authors.forename: A
authors.initials: A
authors.lastname: Enjalbert
mesh_terms: D000172:Acromegaly / Q000378:metabolism; D000236:Adenoma / Q000378:metabolism*; D005260:Female; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism*; D006801:Humans; D008297:Male; D010911:Pituitary Neoplasms / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017481:Receptors, Somatostatin; D013004:Somatostatin / Q000031:analogs & derivatives / Q000378:metabolism; D053561:Somatostatin-28
chemical_list: D011956:Receptors, Cell Surface; D017481:Receptors, Somatostatin; C017426:somatostatin, iodine-Tyr-; D013004:Somatostatin; D053561:Somatostatin-28; D011388:Prolactin; D013006:Growth Hormone