1. Departamento de Farmacobiología, Cinvestav-Coapa, Czda. de los Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F
2. Department of Internal Medicine, Division of Vascular Medicine and Pharmacology, Erasmus University Medical Center, P.O. Box 2040, 3000 CA Rotterdam