Fig. 1

Effect of low-frequency, low-force cyclic stretching on bronchial basal tone and responsiveness to acetylcholine. The illustration is based on a representative experiment. ACh, acetylcholine; CRC, concentration-response curves for ACh; (1), resting basal tone; (2), maximal bronchial contraction in response to 3 mM ACh, before cyclic stretching; (3), pre-stretching bronchial tone; (4), bronchial tone at rest immediately after the end of cyclic stretching; (5), post-stretching bronchial tone within 10 min following the cyclic stretching period; (6) maximal bronchial contraction in response to 3 mM ACh after cyclic stretching. In the control group, bronchial tone did not change significantly between points 4 and 6 (data not shown) (20)