1. Department of Pathology, University of Pisa, Pisa, Italy
2. Department of Medicine, University of Pisa, Pisa, Italy
3. National Research Council, Institute of Clinical Physiology, Pisa, Italy
4. Muscle Research Unit, Bosch Institute, The University of Sydney, Sydney, Australia
5. Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands