抄録
We previously reported that intrathecal administration of various local anesthetics resulted in the dorsal root axonal degeneration near entry into the spinal cord in rats. The level of neurotoxicity of local anesthetics in the dorsal root depended on the kind of anesthetics and this was comparable to the level of side effects occurred in the clinical use. In the present study, we assessed the effects of various local anesthetics on axonal transport in cultured mouse dorsal root ganglion neurons. Lidocaine, bupivacaine, and ropivacaine (concentrations: 1-50 mM) all decreased axonal transport, but in different degree. The order of potency was lidocaine<bupivacaine<ropivacaine. At a concentration of 50 mM, lidocaine and bupivacaine but not ropivacaine caused the rupture of plasma membrane in some dorsal root ganglion neurons. Considering with the pharmacological potency, lidocaine:bupivacaine:ropivacaine = 1:4:4, the neurotoxocity of ropivacaine is likely much less than that of lidocaine. These in vitro experiments may be useful for determining the neurotoxicity of local anesthetics. [J Physiol Sci. 2006;56 Suppl:S119]
