Abstract: AIM: To study the changes of ERK mitogen-activated protein kinase (ERK-MAPK) /NF-κB in peripheral blood mononuclear cells ( PBMCs) in rats with bronchial asthma and the effects of erythromycin on it. METHODS: PBMCs were collected and cultured from rats with bronchial asthma, normal subjects and erythromycin-treated groups. The ERKmRNA, NF-κB mRNA and phosphor protein of ERK, NF-κB in PBMCs were detected by reverse transcription polymerase chain reaction (RT-PCR) and western blotting respectively. RESULTS: The expression of ERK mRNA, NF-κB mRNA, phosphor-ERK, phosphor-NF-κB in PBMCs were higher in asthmatic group than those in normal group (P<0.05). With the treatment of erythromycin, the above indexes were decreased significantly compared with those in asthmatic group (all P<0.05). There were positive correlations between the expression of phosphor- ERK and phosphor-NF-κB in PBMCs (r=0.693, P<0.05). CONCLUSION: ERK and NF-κB may play a role in pathophysiological process of asthma. Erythromycin could effectively exert its anti-inflammatory effect by ERK / NF-κB signaling pathway.

Key words: Asthma, Peripheral blood mononuclear cell, ERK mitogen-activated protein kinase, NF-κB, Erythromycin