Effect of capsaicin on voltage-gated currents of trigeminal neurones in cell culture and slice preparations.
Acta Physiol Hung
; 88(3-4): 173-96, 2001.
Article
em En
| MEDLINE
| ID: mdl-12162577
ABSTRACT
Effects of capsaicin on voltage-gated currents were examined in vitro by whole-cell patch-clamp recordings from small neurones of rat trigeminal ganglia either in slice preparations or in different cell cultures. Cells were classified as sensitive to capsaicin if they responded with inward current and/or conductance change to the agent in nanomolar concentration. Capsaicin (150 to 330 nM) in sensitive cells reduced the mixed inward current evoked by depolarizing step or ramp commands in all preparations. In cultured cells, the inward current was depressed to 32.78 +/- 26.42% (n = 27) of the control. Both the tetrodotoxin-sensitive and -resistant inward currents were affected. The data support the concept that capsaicin besides acting on VR-1 receptors inhibits also some voltage gated channels. In 34 cultured cells, capsaicin increased the slope conductance to 170.5 +/- 68%. Percentage of capsaicin sensitive cells observed in nerve growth factor-treated cultured cell populations was higher (77.8%) than in the two other preparations (14.3 or 38.8%). It is concluded that 1) depression of the voltage-gated currents may play an important role in the functional desensitization of the sensory receptors and in the analgesic effect induced by the agent and 2) cell body of sensory neurones under native condition seems less sensitive to capsaicin then that of cells cultured in the presence of nerve growth factor.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Capsaicina
/
Gânglio Trigeminal
/
Neurônios Aferentes
Limite:
Animals
Idioma:
En
Revista:
Acta Physiol Hung
Ano de publicação:
2001
Tipo de documento:
Article