Artículo
Thyrotropin-releasing-hormone (TRH) and its physiological metabolite TRH-OH inhibit Na+ channel activity in mammalian septal neurons
Autor/es | López Barneo, José
Castellano Orozco, Antonio Gonzalo Toledo Aral, Juan José |
Departamento | Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica |
Fecha de publicación | 1990 |
Fecha de depósito | 2015-01-14 |
Publicado en |
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Resumen | The interaction of thyrotropin-releasing hormone (TRH) and its physiological metabolite TRH-OH with Na+ channels was studied in enzymatically dissociated guinea pig septal neurons by using the whole-cell variant of the ... The interaction of thyrotropin-releasing hormone (TRH) and its physiological metabolite TRH-OH with Na+ channels was studied in enzymatically dissociated guinea pig septal neurons by using the whole-cell variant of the patch-clamp technique. In about 60% of the cells tested, the neuropeptides at concentrations between 0.01 and 2.5 ,uM produced a dose-dependent reversible attenuation of Na+ currents. With 2 ,uM TRH-OH, peak Na+ current amplitude was reduced by 20-50% (27 ± 8%, mean ± SD; n = 16), whereas at the same concentration TRH was approximately half as effective as TRH-OH. In the presence of the tripeptides, the voltage-dependent parameters of the Na+ current were unaltered. TRH-induced reduction of Na+ current amplitude was transient and recovered almost completely during maintained exposure to the peptides. In addition, the response to either TRH-OH or TRH decreased with repeated treatment. Our results demonstrate that neuronal Na+ channels can be modulated by naturally occurring neuropeptides. |
Cita | López Barneo, J., Castellano Orozco, A.G. y Toledo Aral, J.J. (1990). Thyrotropin-releasing-hormone (TRH) and its physiological metabolite TRH-OH inhibit Na+ channel activity in mammalian septal neurons. Proceedings of the National Academy of Sciences of the United States of America, 87 (20), 8150-8154. |
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