1. From the C.N.R. Institute of Clinical Physiology (M.A.C., M.A.A., M.M, E.S., A.D.), Lecce; Department of Biology (L.S., C.S.), University of Lecce; Institute of Pharmacological Sciences (F.V), School of Pharmacy, University of Milan; and Chair of Cardiology (R.D.C.), “G. d’Annunzio” University, Chieti, Italy.