1. From the Department of Physiology and Hypertension and Renal Center of Excellence (M.C.P.-C., F.T.B., J.P., H.K., D.M.S., L.G.N.), Tulane University Health Sciences Center, New Orleans, La; Department of Physiology and Pharmacology (M.C.P.-C., J.P.), Ponce School of Medicine, Ponce, Puerto Rico; and Nephrology Division (D.E.C.), Department of Medicine, Federal University of Sao Paulo, Sao Paulo, Brazil.