Chronic ethanol exposure in PKC dominant-negative PC12 cells. Ethanol (100 mM for 96 hours) has no effect on microtubule or tubulin content in dominant-negative delta PC12 cells (A). Ethanol significantly increased microtubule content and decreased tubulin content in dominant-negative epsilon cells (B). The graphs represent the combined data from three independent replications of the same experiment (n = 6). Data are presented as the mean +/- SEM. Asterisks represent significant differences from corresponding control (p < 0.005).