Introduction Although pathogenesis of asthma is still a major challenge in medical science,it is generally agreed that both structural and functional alterations of airway smooth muscle (ASM) are the common final pathway responsible for the excessive con- Introduction Although pathogenesis of asthma is still a major challenge in medical science, it is generally agreed that both both structural and functional alterations of airway smooth muscle (ASM) are the common final pathway responsible for the excessive con-