1. Department of Clinical Pharmacology and Therapeutics Hamamatsu University School of Medicine 3600 Handa‐cho Hamamatsu 431‐3192
2. Department of Pharmacology Hokkaido University School of Medicine Sapporo 060‐8638
3. Department of Geriatric Medicine Nagoya University School of Medicine Nagoya 466‐8560
4. Life Science Research Center Asahi Chemical Industry Company, Ltd. Fuji 416‐0934 Japan