1. Department of Pharmacology, Faculty of Medicine, Kyoto University, Kyoto 606, Japan
2. Second Department of Internal Medicine, Gifu University School of Medicine, Gifu, Japan
3. Department of Bioscience, National Cardiovascular Center Research Institute, Suita, Osaka 565–8565, Japan
4. Department of Pediatric Cardiology, Heart Institute of Japan, Tokyo Women's Medical College, Tokyo, Japan
5. Chromosome Research Unit, Faculty of Science, Hokkaido University, Sapporo, Japan