ω-agatoxin IVA blocks nicotinic receptor channels in bovine chromaffin cells
We have studied the contribution of P-type voltage-dependent Ca2+ channels to both catacholamine (CA) and ATP secretion from bovine chromaffin cells induced by high K+ or nicotine using ω-agatoxin IVA, a selective blocker of P-type voltage-dependent Ca2+ channels. We found that high K+ (75 mM) induc...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 1995 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/288500 |
| Acceso en línea: | http://hdl.handle.net/10261/288500 |
| Access Level: | acceso abierto |
| Palabra clave: | Calcium channel P-type Nicotinic receptor ω-Agatoxin IVA Secretion Chromaffin cell |
| Sumario: | We have studied the contribution of P-type voltage-dependent Ca2+ channels to both catacholamine (CA) and ATP secretion from bovine chromaffin cells induced by high K+ or nicotine using ω-agatoxin IVA, a selective blocker of P-type voltage-dependent Ca2+ channels. We found that high K+ (75 mM) induced the release of about 13% of norepinephrine, 5% epinephrine and 11% ATP, and that ω-agatoxin (100 nM) did not affect this secretion. However, both nicotine-induced CA and ATP secretion were significantly blocked (about 50%) by ω-agatoxin IVA (100 nM). In addition, this toxin also reversibly blocked (about 70%) the inward current induced by nicotine in bovine chromaffin cells. The results suggest that, besides its known action of blocking P-type voltage-dependent channels, ω-agatoxin is a potent and reversible blocker of the nicotinic receptor channel in chromaffin cells, and that this action would explain the blockade of nicotine-induced secretion. |
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