1. From the Departments of Internal Medicine (J.L.P., R.D.L., D.D., H.Z., B.KD., J.C., K.B.A., M.S., A.K.K., F.C.B.) and Physiology (R.D.L., F.C.B.), University of Michigan Medical School, Ann Arbor, Mich; the Department of Biochemistry (M.J.C.), Albert Einstein College of Medicine, Bronx, NY; and the Hypertension and Vascular Research Division (N.A., P.J.P.), Henry Ford Hospital, Detroit, Mich.