1. Institute of Physiology I, Life and Brain Center, Medical Faculty, University of Bonn, Bonn, Germany.
2. Pharmacology Research Group, University Hospital of Nottingham, Nottingham, UK.
3. Molecular, Cellular, and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, Bonn, Germany.
4. Pharmaceutical Institute, Institute of Pharmaceutical Chemistry I, University of Bonn, Bonn, Germany.
5. Institute of Pharmaceutical Biology, University of Bonn, Bonn, Germany.
6. PharmaCenter, University of Bonn, Bonn, Germany.
7. Division of Respiratory Medicine, University Hospital of Nottingham, Nottingham, UK.