Cytotoxic actions of lidocaine at sublethal concentrations : A model in vitro experiment using rat thymocytes
In order to reveal some cytotoxic features of lidocaine, the effects of lidocaine at sublethalconcentrations (10 mM or less) on rat thymocytes were examined by the use of flow-cytometrictechnique with fluorescent probes. Treatment with lidocaine at 3-10 mM for 1-3 hrsignificantly increased intracellular Ca2+ and Zn2+ concentrations under normal condition.After the removal of external Ca2+ and Zn2+, lidocaine still increased intracellular Ca2+ and Zn2+concentrations, suggesting the lidocaine-induced release of intracellular Ca2+ and Zn2+.Treatment with lidocaine at 0.3-1 mM for 24 hr significantly increased the populations of deadcells and shrunken cells. Lidocaine at sublethal concentrations exerts some cellular actionsthat are supposed to be linked to the cytotoxicity. The mechanism of lidocaine-induced celldeath varies in time- and concentration-dependent manners.
徳島大学総合科学部自然科学研究 24, 1-5, 2010