1. Laboratory of Veterinary Pharmacology Nippon Veterinary and Life Science University, Kyonan-cho 1-chome, Musashino, Tokyo 180-862, Japan
2. Laboratory of Veterinary Biochemistry Nippon Veterinary and Life Science University, Kyonan-cho 1-chome, Musashino, Tokyo 180-862, Japan
3. Laboratory of Veterinary Physiology Nippon Veterinary and Life Science University, Kyonan-cho 1-chome, Musashino, Tokyo 180-862, Japan