Effects of bupivacaine on membrane currents of guinea-pig ventricular myocytes.
The effects of bupivacaine on the membrane currents of single guinea-pig ventricular myocytes were investigated using the whole-cell patch-clamp technique. Bupivacaine decreased the inward calcium current in a concentration-dependent way at concentrations of 10 microM and higher. Bupivacaine also decreased the delayed outward current without modifying the inward-rectifying potassium current. From these results it can be concluded that bupivacaine, at concentrations lower than 10 microM, does not exert its negative inotropic effect by decreasing the calcium current. This mechanism may play a role at higher concentrations of the drug.
Sánchez-Chapula
J
J
Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, México.
D000818:Animals; D002045:Bupivacaine / Q000494:pharmacology*; D002121:Calcium Channel Blockers; D015220:Calcium Channels / Q000187:drug effects; D004594:Electrophysiology; D005260:Female; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006352:Heart Ventricles / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D015221:Potassium Channels / Q000187:drug effects; D016276:Ventricular Function
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D015221:Potassium Channels; D002045:Bupivacaine