Effect of halothane on the release of [Ca2+]i in dorsal root ganglion neurons.

We investigated the effect of the volatile anaesthetic halothane on [Ca 2+ ] i of dorsal root ganglion neurons. Halothane was able to increase [Ca 2+ ] i in those neurons in a dose-dependent manner and independent of extracellular calcium. However, halothane action was inhibited by BAPTA-AM, suggesting the involvement of intracellular calcium stores. Dantrolene, an inhibitor of ryanodine-sensitive calcium stores had no effect while 2-APB, an inhibitor of IP 3 -sensitive calcium store reduced by 78% the halothane-evoked increase on [Ca 2+ ] i . These data suggests that halothane increased [Ca 2+ ] i of ganglion neurons through calcium release from IP 3 -sensitive calcium store. One possible consequence of the halothane action is to alter presynaptic activity and signaling pathways that influence neurotransmission.