The permeant molecule urea stimulates prolactin secretion in GH4C1 cells by inducing Ca2+ influx through dihydropyridine-sensitive Ca2+ channels.
Mol Cell Endocrinol
; 70(3): 273-9, 1990 May 07.
Article
en En
| MEDLINE
| ID: mdl-2163337
ABSTRACT
Isotonic urea in medium with a normal 1.2 mM Ca2+ concentration induced a striking rise in both cytosolic Ca2+ concentration ([Ca2+]i) and prolactin (PRL) secretion, each of whose peaks were proportional to the concentration of urea between 5 and 120 mM. There was a significant linear relationship between the peaks of induced [Ca2+]i and PRL secretion (r = 0.99, P less than 0.001). The increase in both [Ca2+]i and PRL secretion was completely abolished by removal of medium Ca2+ or by 2 microM nifedipine. Hypertonic urea was ineffective in inducing either an increase in [Ca2+]i or PRL secretion. These data support the hypothesis that plasma membrane expansion is a potent non-toxic inducer of hormone secretion and that in GH4C1 cells an increase in [Ca2+]i produced by enhanced influx of extracellular Ca2+ through dihydropyridine-sensitive Ca2+ channels plays an important role in this phenomenon.
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Banco de datos:
MEDLINE
Asunto principal:
Prolactina
/
Urea
/
Canales de Calcio
/
Calcio
Tipo de estudio:
Diagnostic_studies
Límite:
Animals
Idioma:
En
Año:
1990
Tipo del documento:
Article