Figure 4.

Relaxation of airway smooth muscle. Human bronchial rings were pre-contracted with anti-IgE (1:300) and once the contraction had plateaued, the effects of cumulative additions of (A) isoprenaline and (B) long-acting β-agonists on the contraction determined. The control contraction was 1.5 ± 0.3 g. Results are expressed as a percentage of the maximal relaxation observed with 30 µmol·L⁻¹ isoprenaline. Values are means ± SEM, n= 4–5.