The growth hormone secretagogue, L-692,429, induces phosphatidylinositol hydrolysis and hormone secretion by human pituitary tumors.

Abstract

L-692,429 is a non-peptidyl GH secretagogue. We examined the effects of L-692,429 on cultured human pituitary tumors removed from patients with acromegaly. Dose-dependent stimulation of GH secretion was observed, with 1 mumol/L leading to 2 or 3-fold increases. Prolactin (PRL) secretion by a mixed somatotrophic-lactotrophic tumor was also stimulated. The effects of L-692,429 were abolished by phloretin and W7 but not Rp-cAMPS. Rate of phosphatidylinositol turnover was markedly increased up to 3-fold by L-692,429. These results show that L-692,429 increases hormone secretion by human pituitary cells via a protein kinase C and Ca2+ dependent mechanism.

• Authors: E F Adams, B Petersen, T Lei, M Buchfelder, R Fahlbusch
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 208 Issue 2 Pg. 555-61 (Mar 17 1995) ISSN: 0006-291X [Print] United States
• PMID: 7695607 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Benzazepines
• Calmodulin
• Oligopeptides
• Phosphatidylinositols
• Tetrazoles
• L 692429
• growth hormone releasing hexapeptide
• Prolactin
• Growth Hormone
• Growth Hormone-Releasing Hormone
• Protein Kinase C
• Phloretin

Topics

• Acromegaly (metabolism)
• Adult
• Benzazepines (pharmacology)
• Calmodulin (antagonists & inhibitors)
• Female
• Growth Hormone (metabolism)
• Growth Hormone-Releasing Hormone (pharmacology)
• Humans
• In Vitro Techniques
• Oligopeptides (pharmacology)
• Phloretin (pharmacology)
• Phosphatidylinositols (metabolism)
• Pituitary Neoplasms (metabolism)
• Prolactin (metabolism)
• Protein Kinase C (antagonists & inhibitors)
• Second Messenger Systems
• Tetrazoles (pharmacology)
• Tumor Cells, Cultured