CCKA receptors mediate slow depolarizations in cultured mammalian sympathetic neurons.
Eur J Pharmacol
; 232(1): 65-9, 1993 Feb 23.
Article
em En
| MEDLINE
| ID: mdl-8458396
The effect of cholecystokinin octapeptide (CCK-8) was examined in guinea-pig celiac ganglion (CG) neurons in primary culture using standard intracellular recording techniques. Sulfated CCK-8 (CCK-8S; 1 microM) evoked slow depolarizing responses in 94% of CG neurons tested. In contrast, membrane potential was not affected by nonsulfated CCK-8 (CCK-8NS; 1 microM), CCK tetrapeptide (CCK-4; 1 microM), or gastrin (1 microM). The selective CCKA receptor antagonist L 364,718 potently inhibited CCK-8S-induced slow depolarizations (IC50 2.9 pM). In contrast, the selective CCKB receptor antagonist L 365,260 was a weak inhibitor of CCK-8S-induced slow depolarizations (IC50 1.3 microM). The depolarizing responses to CCK-8S were associated with an average increase in cell input resistance of 61%. Single electrode voltage clamp experiments indicated that CCK-8S-induced depolarizations were associated with a slow inward shift in holding current. Thus, the present findings indicate that guinea-pig cultured CG neurons are endowed with excitatory CCKA receptors the activation of which elicits a decrease in membrane conductance, thereby resulting in slow depolarizations.
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Base de dados:
MEDLINE
Assunto principal:
Compostos de Fenilureia
/
Receptores da Colecistocinina
/
Gânglios Simpáticos
Limite:
Animals
Idioma:
En
Ano de publicação:
1993
Tipo de documento:
Article