1. Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha (K.P.P.).
2. Division of Cardiovascular Medicine, Department of Internal Medicine (K.K.), Jichi Medical University School of Medicine, Shimotsuke, Tochigi, Japan.
3. Division of Clinical Pharmacology, Department of Pharmacology (K.K.), Jichi Medical University School of Medicine, Shimotsuke, Tochigi, Japan.
4. Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion (H.Z.).