1. From the Clinical Pharmacology Unit (N.D., J.G., D.J.W.), University of Edinburgh, Queen’s Medical Research Institute, Edinburgh, United Kingdom; Division of Nephrology (D.E.K.), University of Utah, Salt Lake City; Vascular Biology Center (D.M.P.), Medical College of Georgia, Augusta; and Department of Medicine (E.L.S.), Sir Mortimer B. David-Jewish General Hospital, McGill University, Montreal, Quebec, Canada.