Effect of GnRH-associated peptide on prolactin secretion from human lactotrope adenoma cells in culture.
The effect of GnRH-associated peptide on PRL secretion by human pituitary lactotropes in culture was studied. Pituitary adenomas obtained at selective transsphenoidal adenomectomy from a patient with prolactinoma, and two patients with mixed GH- and PRL-secreting pituitary adenomas were cultured in monolayer. When cells were incubated with dopamine (10 nmol/l), a significant inhibition in PRL secretion was observed in all the experiments, which was blocked by co-incubation with haloperidol. In mixed GH- and PRL-secreting adenoma cells, dopamine likewise decreased GH secretion. Incubation of cells with synthetic GnRH-associated peptide at concentrations up to 100 nmol/l, on the other hand, failed to affect both PRL and GH secretion. These results suggest that synthetic GnRH-associated peptide has no inhibitory effect on PRL secretion in human pituitary lactotropes.
Ishibashi
M
M
Third Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
Yamaji
T
T
Takaku
F
F
Teramoto
A
A
Fukushima
T
T
Toyama
M
M
Kamoi
K
K
D000236:Adenoma / Q000378:metabolism*; D000328:Adult; D002478:Cells, Cultured; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D010906:Pituitary Hormone-Releasing Hormones / Q000494:pharmacology*; D010911:Pituitary Neoplasms / Q000378:metabolism*; D011388:Prolactin / Q000097:blood / Q000378:metabolism*; D011498:Protein Precursors / Q000494:pharmacology*; D011863:Radioimmunoassay
D010906:Pituitary Hormone-Releasing Hormones; D011498:Protein Precursors; C050502:gonadotropin releasing hormone associated peptide; D007987:Gonadotropin-Releasing Hormone; D011388:Prolactin; D013006:Growth Hormone