1. From the Department of Physiology (D.L., A.M., J.K., S.-S.B.) and the Heart & Stroke/Richard Lewar Centre of Excellence in Cardiovascular Research (S.-S.B.), University of Toronto, Canada; the Institute of Physiology (B.F.P.), Walter-Brendel-Centre of Experimental Medicine (U.P.), Ludwig-Maximilians-University, Munich, Germany; and the Hanson Institute, Human Immunology (S.M.P.), Institute of Medical and Veterinary Science, Adelaide, Australia.