1. From the Department of Pharmacology and INSERM U 337 (P.B., C.B., B.L., S.L.), Broussais Hospital, Paris, France; Rhône-Poulenc-Rorer (N.D.), Paris, France; and Division of Hypertension and Vascular Medicine, CHUV (D.H., J.H., H.B.), Lausanne, Switzerland.