The effects of melatonin daily supplementation to aged rats on the ability to withstand cold, thermoregulation and body weight.

Aims: Investigate the role of melatonin on the regulation of body temperature in aged animals that have impaired melatonin production.

Material And Methods: Aged Male Wistar rats were randomly assigned to the following groups: 1) control (vehicle added to the water bottles during the dark phase) and 2) melatonin-treated (10 mg/kg melatonin added to the water bottles during the dark phase). Before and after 16 weeks of vehicle or melatonin treatment, control group and melatonin-treated animals were acutely exposed to 18 °C for 2 h for an acute cold challenge and thermal images were obtained using an infrared camera.