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: M Le Dafniet, P Garnier, D Bression, A M Brandi, J Racadot, F Peillon
• Journal: Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme (Horm Metab Res) Vol. 17 Issue 9 Pg. 476-9 (Sep 1985) ISSN: 0018-5043 [Print] Germany
• PMID: 2864309 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Receptors, Cell Surface
• Receptors, Thyrotropin-Releasing Hormone
• Gonadotropin-Releasing Hormone
• Somatostatin
• gamma-Aminobutyric Acid
• Thyrotropin-Releasing Hormone
• Growth Hormone

Topics

• Adenoma (metabolism)
• Cell Membrane (metabolism)
• Gonadotropin-Releasing Hormone (metabolism)
• Growth Hormone (metabolism)
• Humans
• Pituitary Neoplasms (metabolism)
• Receptors, Cell Surface (metabolism)
• Receptors, Thyrotropin-Releasing Hormone
• Somatostatin (metabolism)
• Thyrotropin-Releasing Hormone (metabolism)
• gamma-Aminobutyric Acid (metabolism)