Electrophysiological effects of capsaicin on spontaneous activity of rabbit atrioventricular node cells / 生理学报
Acta Physiologica Sinica
;
(6): 248-252, 2004.
Article
Dans Anglais
| WPRIM
| ID: wpr-352785
ABSTRACT
To study the electrophysiological effects of capsaicin on spontaneous activity of rabbit atrioventricular (AV) node cells, parameters of action potential in AV node were recorded using intracellular microelectrode technique. Capsaicin (1-30 micromol/L) not only decreased the amplitude of action potential, maximal rate of depolarization (V(max)), velocity of diastolic (phase 4) depolarization, and rate of pacemaker firing, but also prolonged the duration of 90% repolarization of action potential (APD(90)) in a concentration-dependent manner. Both application of L-type Ca(2+) channel agonist Bay K8644 (0.5 micromol/L) and elevation of calcium concentration (5 mmol/L) in superfusate antagonized the effects of capsaicin on pacemaker cells. Pretreatment with ruthenium red (10 micromol/L), a capsaicin receptor blocker, did not affect the effects of capsaicin on AV node cells. Capsaicin exerted an inhibitory action on spontaneous activity of AV node cells in rabbits. These effects were likely due to reduction in calcium influx, but were not mediated by VR1.
Texte intégral:
Disponible
Indice:
WPRIM (Pacifique occidental)
Sujet Principal:
Pharmacologie
/
Physiologie
/
Récepteurs des médicaments
/
Rouge de ruthénium
/
Noeud atrioventriculaire
/
Potentiels d'action
/
Agonistes des canaux calciques
/
Capsaïcine
/
4-(2-(Trifluorométhyl)phényl)-2,6-diméthyl-5-nitro-1,4-dihydro-nicotinate de méthyle
/
Calcium
Limites du sujet:
Animaux
langue:
Anglais
Texte intégral:
Acta Physiologica Sinica
Année:
2004
Type:
Article
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