The level of MAPK molecule (ERK1, ERK2, p38α and JNK1) mRNA expression in rat cerebral arteries (A). Activation of Raf-1 protein expression in rat cerebral arteries (B). Activation of ERK1/2 protein expression in rat cerebral arteries (C). The cerebral arteries were isolated from groups of fresh air, SHS and SHS treatment with GW5074. The key MAP kinases mRNA was relative to GAPDH (n = 5-6); and the p-Raf-1 and p-ERK1/2 protein were relative to Raf-1 or ERK1/2 level (n = 5). *P < 0.05, **P < 0.01 versus fresh air group, #P < 0.05 versus SHS group, ns not significant; SHS, secondhand smoke exposure; GW, GW5074 (0.5 mg/kg).