Fig. 4.

Effect of ethanol (ETOH) and hydrogen peroxide on PKC-ζ/LKB1 and its downstream target proteins. H4IIEC3 cells were grown as described for Fig. 1 followed by treatment for times indicated with control, ethanol (50 mM) for 24 h, H₂O₂ 1 mM for 10 min, and pretreatment with ethanol 24 h before H₂O₂ exposure. Western blots (A) were quantified by a PhosphorImager and ImageQuant software analysis (bar graph, B). Ethanol reduced the level of p-PKC-ζ and p-LKB1 by ∼40% and ∼60% in the H4IIEC3 cells compared with controls; on the other hand, H₂O₂ significantly increased its phosphorylation (by 3-fold) (P < 0.05). *Significant difference vs. control; $significant difference compared with pretreatment with ethanol.