1. From the Department of Cardiovascular Biology (V.J.K.), Millennium Pharmaceuticals Inc, Cambridge, Mass; the Department of Medicine (B.D.H.), Case Western Reserve University, Cleveland, Ohio; and the Departments of Pharmacology (R.D., A.G.S., N.M.T., M.J.G., S.B.L., G.W.D., E.G.K.), Physiology (J.N.L., E.G.K.), and Medicine (D.B., A.M.C., W.T.A., S.B.L., G.W.D.), University of Cincinnati College of Medicine, Cincinnati, Ohio.