TY - JOUR
T1 - Effect of local anesthetic on neuronal cytoplasmic calcium and plasma membrane lysis (necrosis) in a cell culture model
AU - Johnson, Michael E.
AU - Saenz, J. Armando
AU - DaSilva, Assir Daniel
AU - Uhl, Cindy B.
AU - Gores, Gregory J.
PY - 2002/12/1
Y1 - 2002/12/1
N2 - Background: To investigate the mechanism by which rare cases of spinal local anesthetic (LA) neurotoxicity occur, we have tested the hypotheses that LAs elevate cytoplasmic calcium (Ca2+cyt), that this is associated with a neurotoxic effect, and that lidocaine and bupivacaine differ in their neurotoxicity. Methods: Neurons of the ND7 cell culture line, derived from dorsal root ganglion, were loaded with fura-2 and analyzed by digitized video fluorescence microscopy during 60 min LA exposure, allowing determination of Ca2+cyt and time of necrotic cell death (plasma membrane lysis) at the single neuron level. Results: Lidocaine 0.1% and bupivacaine 0.025% caused minimal changes in Ca2+cyt. Lidocaine 0.5-5% and bupivacaine 0.125-0.625% caused an early, small (less than threefold), concentration-dependent increase in Ca2+cyt that was transient and returned to near baseline within 10 min. Lidocaine 2.5% and 5% then caused a sustained, greater than ten-fold increase in Ca2+cyt and death in some neurons during the 60 min exposure period. Pretreatment with thapsigargin eliminated the initial transient increase in Ca2+cyt, consistent with endoplasmic reticulum (ER) as its source, and increased neuronal death with 5% lidocaine, suggesting that lidocaine neurotoxicity can be increased by failure of ER to take up elevated Ca2+cyt. The later sustained increase in Ca2+cyt seen with 2.5 and 5% lidocaine was prevented in Ca2+-free medium, and restored when Ca2+ was added back to the buffer in the presence of lidocaine, suggesting that higher concentrations of lidocaine increase influx of Ca2+ through the plasma membrane. Conclusions: In this model, lidocaine greater than 2.5% elevates Ca2+cyt to toxic levels. Bupivacaine and lower concentrations of lidocaine transiently alter Ca2+cyt homeostasis for several minutes, but without an immediate neurotoxic effect within 60 min.
AB - Background: To investigate the mechanism by which rare cases of spinal local anesthetic (LA) neurotoxicity occur, we have tested the hypotheses that LAs elevate cytoplasmic calcium (Ca2+cyt), that this is associated with a neurotoxic effect, and that lidocaine and bupivacaine differ in their neurotoxicity. Methods: Neurons of the ND7 cell culture line, derived from dorsal root ganglion, were loaded with fura-2 and analyzed by digitized video fluorescence microscopy during 60 min LA exposure, allowing determination of Ca2+cyt and time of necrotic cell death (plasma membrane lysis) at the single neuron level. Results: Lidocaine 0.1% and bupivacaine 0.025% caused minimal changes in Ca2+cyt. Lidocaine 0.5-5% and bupivacaine 0.125-0.625% caused an early, small (less than threefold), concentration-dependent increase in Ca2+cyt that was transient and returned to near baseline within 10 min. Lidocaine 2.5% and 5% then caused a sustained, greater than ten-fold increase in Ca2+cyt and death in some neurons during the 60 min exposure period. Pretreatment with thapsigargin eliminated the initial transient increase in Ca2+cyt, consistent with endoplasmic reticulum (ER) as its source, and increased neuronal death with 5% lidocaine, suggesting that lidocaine neurotoxicity can be increased by failure of ER to take up elevated Ca2+cyt. The later sustained increase in Ca2+cyt seen with 2.5 and 5% lidocaine was prevented in Ca2+-free medium, and restored when Ca2+ was added back to the buffer in the presence of lidocaine, suggesting that higher concentrations of lidocaine increase influx of Ca2+ through the plasma membrane. Conclusions: In this model, lidocaine greater than 2.5% elevates Ca2+cyt to toxic levels. Bupivacaine and lower concentrations of lidocaine transiently alter Ca2+cyt homeostasis for several minutes, but without an immediate neurotoxic effect within 60 min.
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U2 - 10.1097/00000542-200212000-00019
DO - 10.1097/00000542-200212000-00019
M3 - Article
C2 - 12459673
AN - SCOPUS:18744381256
SN - 0003-3022
VL - 97
SP - 1466
EP - 1476
JO - Anesthesiology
JF - Anesthesiology
IS - 6
ER -