Fig. 3

Length relaxation of bronchial rings during an isotonic contraction after 3 cycles of force oscillation (0.25 Hz). The dashed horizontal line represents acetylcholine (ACh)-induced shortening of the ring preparation maintained over time (time control) without interruption by the force oscillation. The oscillation was applied during an isotonic contraction at three different times (5, 15, and 60 min) after the onset of contraction. The solid black symbols represent measurements that are significantly different from the time control with a P value < 0.01, and the gray symbols represent measurements that are significantly different from the time control with a P value < 0.05. The open symbols indicate no difference from time control. Reproduced from Dong et al. [24] with permission