Fig. 1. (A ) Time course of tetracaine-induced cell death. PC12 cells were treated with indicated concentrations of tetracaine for indicated periods and then stained with 0.5% trypan blue. Cell death was evaluated. Data represent mean ± SD of three different experiments, each conducted in duplicate. ***P < 0.0001 versus 0 mm, **P < 0.0005 versus 0 mm, *P < 0.05 versus 0 mm at the same time point. (B ) Tetracaine-induced lactate dehydrogenase (LDH) release from PC12 cells. Cultured cells were challenged with indicated concentrations of tetracaine for 10 h, and LDH activity released in the media was assayed. Data shown are mean ± SD from two different experiments, each conducted in triplicate. ***P < 0.0001 versus 0 mm, **P < 0.0005 versus 0 mm.