Fig. 4. Anti-interleukin (IL)-10 antibody and SB203580 inhibit the p38 mitogen-activated protein kinase (MAPK) phosphorylation and heme oxygenase (HO)-1 expression in amitriptyline/morphine coinfused rats. (  A and  B ) Typical blots show expression of p38 MAPK and  phospho -p38 MAPK (  A ) and HO-1 and HO-2 (  B ) protein in the spinal cord dorsal horn of the five groups (n = 4 of each group). β-actin was used as the loading control. (  C and  D ) Pooled densitometric results for p38 MAPK and  phospho -p38 MAPK (  C ) and HO-1and HO-2 (  D ), with the control band intensity assigned the value of 1. CONT = saline infusion; MO = morphine infusion; MO+AMI = morphine plus amitriptyline coinfusion; MO+AMI/Anti-IL-10Ab = morphine plus amitriptyline coinfusion plus anti-IL-10 antibody injection for 5 days; MO+AMI + SB = morphine plus amitriptyline plus SB203580 coinfusion. **  P < 0.01 and ***  P < 0.001 compared with saline group; ###  P < 0.001 compared with morphine group; +++  P < 0.001 compared to the amitriptyline/morphine-coinfused group.