Fig. 3. Western blot analyses of phospho–extracellular signal–regulated kinase 1 and 2 (ERK1/2) and phospho-p38 mitogen-activated protein kinase in anesthetic preconditioning (APC) and ischemic preconditioning (IPC). (A ) ERK1/2 and p38 mitogen-activated protein kinase activity after the application of the preconditioning stimulus (short-term protocol). (B ) ERK1/2 and p38 mitogen-activated protein kinase activity after ischemia–reperfusion injury (long-term protocol) in APC-treated hearts. (C ) ERK1/2 and p38 mitogen-activated protein kinase activity after ischemia–reperfusion injury (long-term protocol) in IPC-treated hearts. Data are presented as mean ± SD. * Significantly increased compared to control (CTL; hearts with time-matched perfusion) or ischemia (ISCH) alone (P < 0.05). † Not significantly different from CTL or ISCH alone. # Significantly higher or lower than respective APC group (P < 0.05). Scale on ordinate  denotes relative change compared to CTL. 5HD = 5-hydroxydecanoate; CHE = chelerythrine; PD = PD98059; SB = SB203580.