Molecular and Mechanical Pathways in Airway Smooth Muscle Relaxation

Chemistry and physics play an important role in relaxing contracted airway smooth muscles (ASM). This work investigates whether combining the two will result in enhanced ASM relaxation. Isolated bovine trachea ASM strips were employed using acetylcholine before undergoing mechanically‐induced length oscillations, consisting of small oscillations superimposed on breathing‐like changes, followed by administration of a broncho‐relaxant agent. The agents used in this work are isoproterenol (ISO), Indomethacin (INDO), SB 203580, or PD 0980590, which are inhibitors of cyclooxygenase extracellular signal‐regulated kinase, 1/2 (ERK1/2), and p38 mitogen‐activated protein kinase, respectively. The ASM reactivity following these treatments is assessed. It is demonstrated that adding one of these agents, Indomethacin, ISO, or SB 203580 enhances the relaxation produced by the oscillation process while it does not work with PD0980590.