1. Department of Pharmacology, Kyungpook National University School of Medicine, Daegu 700-422, Korea.
2. Department of Thoracic and Cardiovascular Surgery, Kyungpook National University School of Medicine, Daegu 700-422, Korea.
3. Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 156-756, Korea.
4. Cardiovascular Research Institute, Kyungpook National University School of Medicine, Daegu 700-422, Korea.