1. From the Department of Pharmacology and Toxicology (J.P., I.Sz., P.K., H.R.) and the Department of Physiology (M.I., O.V.), Biocenter Oulu, University of Oulu, Oulu, Finland; the Heart Institute, Faculty of Medicine, University of Pécs (I.Sz.), Pécs, Hungary; and the First Department of Medicine, Semmelweis University, and Molecular Genetic Research Group of the Hungarian Academy of Science (R.d.C.), Budapest, Hungary.