1. From the Robert M. Berne Cardiovascular Research Center (K.M.O., G.F.A., G.K.O.), University of Virginia, Charlottesville.
2. Department of Biochemistry and Molecular Genetics (K.M.O.), University of Virginia, Charlottesville.
3. Department of Molecular Physiology and Biological Physics (G.K.O.), University of Virginia, Charlottesville.