1. From the Division of Cardiology, Department of Medicine, University of Leicester (V.W., A.F., N.J.S.), UK; Laboratoire de Physiologie EA 645, Faculté de Médecine Grange Blanche, Université de Lyon (L.S., B.Z., M.V.), France; the Departments of Biomedical Services (J.B.) and Biochemistry (C.P.), University of Leicester, UK.