1. Lung Membrane Transport Group, Tayside Institute of Child Health, University of Dundee, Dundee DD1 9SY, UK
2. Department of Animal Physiology, Lund University, S‐223 62 Lund, Sweden
3. Section of Respiratory Medicine, University of Sheffield, Sheffield S10 2RX, UK
4. Department of Toxicology, St Bartholomew's and the Royal London School of Medicine and Dentistry, London EC1 7ED, UK