Journal of receptor and signal transduction research
-
J. Recept. Signal Transduct. Res. · Apr 2010
Effects of levobupivacaine and bupivacaine on intracellular calcium signaling in cultured rat dorsal root ganglion neurons.
Bupivacaine and levobupivacaine have been shown to be effective in the treatment of pain as local anesthetics, although the mechanisms mediating their antinociceptive actions are still not well understood. The aim of this study was to investigate the effects of bupivacaine and levobupivacaine on intracellular calcium ([Ca(2+)](i)) signaling in cultured rat dorsal root ganglion (DRG) neurons. DRG neuronal cultures loaded with 5 microM Fura-2/AM and [Ca(2+)](i) transients for stimulation with 30 mM KCl (Hi K(+)) were assessed by using fluorescent ratiometry. ⋯ Bupivacaine also inhibited Hi K(+)-induced [Ca(2+)](i) responses, reduced to 98.7 +/- 4.8% (n = 10) and 69.5 +/- 4.5% (n = 9, P < 0.05) inhibition of fluorescence ratio values of Hi K(+)-induced responses at 5 and 50 microM, respectively. Our results indicate that bupivacaine and levobupivacaine, with no significant differences between both agents, attenuated KCl-evoked calcium transients in a reversible manner. The inhibition of calcium signals in DRG neurons by levobupivacaine and bupivacaine might contribute to the antinociceptive effects of these local anesthetics.