Actions of L-363,586, a cyclic hexapeptide analogue of somatostatin, on GH secretion by human somatotrophinoma cells in vitro.
L-363,586 is a cyclic, hexapeptide analogue of somatostatin-14 with potent inhibitory actions on rat growth hormone (GH) release in vitro. The studies reported here investigate the direct effects of L-363,586 on basal and growth hormone-releasing factor (GRF)-stimulated GH secretion from 3 human somatotrophinomas in dispersed cell culture. 1nM and 10nM L-363,586 inhibited both basal and GRF-stimulated GH release from cells of all 3 somatotrophinomas during a 2h treatment period, whilst 100nM L-363,586 had a prolonged inhibitory action on basal GH secretion from cells of 2 of the tumours throughout treatment and recovery periods. Rebound release of GH was observed with cells of 1 tumour following treatment with L-363,586 plus GRF. The actions of L-363,586 were similar to those of somatostatin-14. These data suggest that L-363,586 may have a role in the treatment of acromegaly.
Department of Medicine, Medical School, Newcastle upon Tyne, UK.
M
M
Daniels
R A
RA
James
P E
PE
Harris
S J
SJ
Turner
J
J
Dewar
P
P
Kendall-Taylor
D000239:Adenoma, Acidophil / Q000378:metabolism*; D005260:Female; D013006:Growth Hormone / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology; D006801:Humans; D015592:Immunoradiometric Assay; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000494:pharmacology*; D010911:Pituitary Neoplasms / Q000378:metabolism*; D013004:Somatostatin / Q000031:analogs & derivatives* / Q000494:pharmacology; D013223:Statistics as Topic; D014407:Tumor Cells, Cultured
D010456:Peptides, Cyclic; D013004:Somatostatin; C040968:seglitide; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone