Four male rats were randomly divided into two groups.
1) Calpeptin-administration fasting group (n = 2): Calpeptin (Cat. #14593, Cayman Chemical, Ann Arbor, MI) was dissolved in DMSO (20 mg/mL) and intraperitoneally administered at the beginning of the fasting period (0.05 mL), and then again at 24 hr after commencing fasting (0.05 mL).
2) Vehicle-administration fasting group (n = 2): rats were treated as in 1), except that the equivalent amount of vehicle (DMSO) was administered instead of the inhibitor.