1. Divisions of Endocrinology, Diabetes, Hypertension and Metabolism, Diabetes Cardiovascular Center, University of Missouri School of Medicine, Columbia, Missouri;
2. Harry S. Truman Memorial Veterans Hospital, University of Missouri School of Medicine, Columbia, Missouri; and
3. Departments of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri;
4. Dalton Cardiovascular Research Center, University of Missouri School of Medicine, Columbia, Missouri