GABAA and GABAB receptors on porcine pars intermedia cells in primary culture: functional role in modulating peptide release.
Neuroscience
; 17(4): 1275-85, 1986 Apr.
Article
em En
| MEDLINE
| ID: mdl-3012409
ABSTRACT
A primary culture of porcine pars intermedia cells with particularly high yields has been developed. The cells, grown in monolayers, secrete the pro-opiomelanocortin-derived peptide alpha-melanocyte-stimulating hormone over several weeks. The patch-clamp technique has been used to demonstrate the presence of gamma-aminobutyrateA (GABAA) receptors on the cells. GABA or the selective GABAA receptor agonist isoguvacine produced a depolarizing increase in chloride conductance that desensitized rapidly. The response was antagonized by bicuculline and by the aminopyridazine derivative of GABA (SR 95103), a novel GABAA receptor antagonist. The effects of specific agonists for each receptor were tested on peptide release from cells maintained in a perfusion system. Isoguvacine (10 microM) potentiated Ba2+-evoked release of alpha-melanocyte-stimulating hormone, whereas (-)-baclofen (50 microM) decreased both basal and stimulated hormone release. This negative effect on peptide secretion was reproduced when GABA (50 microM) was perfused in the presence of bicuculline (10 microM) to block GABAA receptor activation. The possible mechanisms underlying these GABAA and GABAB effects on stimulus-secretion coupling in this neuroendocrine model are discussed.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hipófise
/
Hormônios Estimuladores de Melanócitos
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Receptores de GABA-A
/
Neurônios
Limite:
Animals
Idioma:
En
Revista:
Neuroscience
Ano de publicação:
1986
Tipo de documento:
Article