Fig. 8.

Effects of MEK inhibitors U-0126 and PD-98059 on p-ERK1/2 and p-p53 expression, PARP activation, and cleaved caspase-3 in neonatal rat cardiomyocytes. Cells were pretreated with or without 20 μM U-0126 or 50 μM PD-98059 for 1 h and then in the presence or absence of 1 μM doxorubicin for 24 h. Whole cell lysates were processed for Western blot analysis of p-ERK1/2, ERK1/2, p-p53, PARP, and active caspase-3. β-actin was used as an equal loading control. Representative Western blots are shown. Data in histograms represent means ± SE from 6 experiments. *P < 0.05, compared with control of the same treatment group; †P < 0.05, compared with doxorubicin treatment alone without MEK inhibitors.