1. Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Korea.
2. Department of Physiology, Dongguk University College of Medicine, Kyungju 780-714, Korea.
3. Department of Internal Medicine, Graduate School of Medicine, Dongguk University, Seoul 100-715, Korea.
4. Ischemia/Hypoxia Disease Institute, Medical Research Center, Seoul National University, Seoul 110-799, Korea.