1. College of Veterinary Medicine, Cheju National University, Jeju 690-756, Korea.
2. Department of Pharmacology, College of Medicine, Cheju National University, Jeju 690-756, Korea.
3. Applied Radiological Science Research Institute, Cheju National University, Jeju 690-756, Korea.
4. The Research Institute for Subtropical Agriculture and Biotechnology, Cheju National University, Jeju 690-756, Korea.