Fasting-induced torpor in Mus musculus and its implications in the use of murine models for human obesity studies

1. 1. Fasting at room temperature for 24–48 hr can induce shallow daily torpor in mice of several strains. 2. 2. Genetically-obese (ob/ob) C57B1/6 mice show torpor even in the presence of food. 3. 3. Chemically-obese (gold-thioglucose or bipiperidyl mustard) mice of C57B1/6 and T/O strains appear resistant to torpor. 4. 4. During cold acclimation (3–5°) fasting also induces torpor in lean mice, with gradually improving rates of arousal. 5. 5. In acute cold shock (3–5°), previously weight-reduced ob/ob mice show resistance to change in body temperature, while control ob/ob mice drift immediately towards hypothermia.