1. Department of Physiology, University of Saskatchewan College of Medicine, 107 Wiggins Road, Saskatoon, SK, Canada S7N 5E5
2. The Medical Affairs Company, Cardiovascular Division, 43229 Dequindre Road, Troy, MI 48085, USA
3. Department of Neurosciences, Psychology, Drug Research and Child Health, Section of Pharmacology and Toxicology, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy