Inhibitory effect of galanin on growth hormone release from rat pituitary tumor cells (GH1) in culture.
The growth hormone (GH) releasing effect of GH-releasing hormone (GHRH) and galanin, a 29-amino acid peptide widely distributed in mammalian CNS, was investigated in cultured rat pituitary tumor cells (GH1) as compared to normal rat somatotrophs. GHRH stimulated dose-dependently GH secretion in normal somatotrophs but did not affect GH secretion in GH1 cells. Galanin (1-10 microM) stimulated GH release in a concentration-dependent manner, but with lower potency as compared to GHRH, in normal rat pituitaries but was inhibitory in rat GH1 cells. The results of this study indicate that while galanin has the ability to stimulate GH release from dispersed pituitary cells of normal rats it has potent direct inhibitory effects on GH release from tumor rat cells.
Giustina
A
A
Sezione di Endocrinologia, School of Medicine, University of Brescia, Italy.
Bonfanti
C
C
Licini
M
M
De Rango
C
C
Milani
G
G
D000818:Animals; D019004:Galanin; D013006:Growth Hormone / Q000037:antagonists & inhibitors* / Q000187:drug effects / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology; D006801:Humans; D008297:Male; D010455:Peptides / Q000494:pharmacology*; D010902:Pituitary Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010911:Pituitary Neoplasms / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014407:Tumor Cells, Cultured
D010455:Peptides; D019004:Galanin; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone