Animals
Male ICR mice (Sankyo Labo Service Corporation, Inc., Shizuoka, Japan)
were used for all animal experiments. The mice were acclimated for 1
week under a 12-hour light/dark cycle with feeding and watering ad
libitum and used for the experiment at 5 weeks of age. The mice were
intraperitoneally injected with cyclophosphamide (Shionogi & Co., Ltd.,
Osaka, Japan) for 4 days (150 mg kg-1) and the day
(100 mg kg-1) before the experiment to decrease their
neutrophils. Protocols of all animal experiments were approved by the
Institutional Animal Care and Use Committee of Keio University (No.
19037) and the Animal Experiment Management Committee, Pharmaceutical
Research Center, Meiji Seika Pharma Co., Ltd.