1. From the Diabetes and Cardiovascular Research Center (G.J., J.R.S.), Columbia, MO.
2. Dalton Cardiovascular Center (G.J., M.A.H., J.R.S.), Columbia, MO.
3. Harry S. Truman Memorial Veterans Hospital (G.J., J.R.S.), Columbia, MO.
4. Department of Medical Pharmacology and Physiology (M.A.H., J.R.S.), Columbia, MO.