American Society of Anesthesiologists

Fig. 7. Effect of local anesthetic (LA) on Ca2+repletion after EGTA-mediated Ca2+depletion: representative single neuron Ca2+cyttracings. Calcium values on y-axis are normalized to the average Ca2+cytfor 5 min prior to buffer Ca2+repletion. Initial buffer was 2 mm Ca2+. Downward arrows indicate addition of EGTA to yield 4 mm EGTA, so that available extracellular Ca2+was approximately 0. Upward arrows indicate addition of LA. Solid arrows indicate lidocaine, dotted arrows indicate bupivacaine experiment. At 0 min, Ca2+was added to yield 4 mm, or approximately 2 mm unchelated extracellular Ca2+. Note log scale on y-axis. In all experiments, EGTA was added 15 to 16 min prior to Ca2+repletion, and LA was added 14 to 15 min prior to Ca2+repletion. In control experiments, there was no increase in Ca2+cytafter the initial small peak when Ca2+was not repleted and the neurons were incubated in Ca2+-free buffer for 45 min after addition of LA (data not shown).

Fig. 7. Effect of local anesthetic (LA) on Ca²⁺repletion after EGTA-mediated Ca²⁺depletion: representative single neuron Ca²⁺^cyttracings. Calcium values on y-axis are normalized to the average Ca²⁺^cytfor 5 min prior to buffer Ca²⁺repletion. Initial buffer was 2 mm Ca²⁺. Downward arrows indicate addition of EGTA to yield 4 mm EGTA, so that available extracellular Ca²⁺was approximately 0. Upward arrows indicate addition of LA. Solid arrows indicate lidocaine, dotted arrows indicate bupivacaine experiment. At 0 min, Ca²⁺was added to yield 4 mm, or approximately 2 mm unchelated extracellular Ca²⁺. Note log scale on y-axis. In all experiments, EGTA was added 15 to 16 min prior to Ca²⁺repletion, and LA was added 14 to 15 min prior to Ca²⁺repletion. In control experiments, there was no increase in Ca²⁺^cytafter the initial small peak when Ca²⁺was not repleted and the neurons were incubated in Ca²⁺-free buffer for 45 min after addition of LA (data not shown).

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