1. Dipartimento di Scienze Farmaceutiche, Universitá di Bologna, Via Belmeloro 6, 40126 Bologna, Italy, Lithuanian Institute of Cardiology, Kaunas, Lithuania LT-3007, Department of Pharmacology, Robert Wood Johnson Medical School, University of Medicine & Dentistry of New Jersey (UMDNJ), 675 Hoes Lane, Piscataway, New Jersey 08854, and Dipartimento di Biochimica “G. Moruzzi”, Universitá di Bologna, Via Irnerio 48, 40126 Bologna, Italy