Metabolic and Endocrine Adaptations to Chronically Low Body Mass in Female Wistar Rats

• Main Author: Gairdner, Sarah
• Other Authors: Amara, Catherine
• Language: en_ca
• Published: 2011
• Subjects: Food Restriction; Endocrinology; Anorexia Nervosa; Metabolism; 0566
• Online Access: http://hdl.handle.net/1807/30601

Animal models have yet to characterize alterations in body composition, wheel running activity, food intake, and neuroendocrine parameters, in chronic food restriction. This study investigated changes in these measures in food restricted rats, with and without access to running wheels, over four weeks. The data demonstrated that upon initiation of food restriction IGF-1 reductions paralleled loss of lean tissue while leptin levels were rapidly reduced which paralleled losses in body fat. Further, a lower limit threshold of body fat was identified, below which the correlation between leptin and fat mass was disrupted. Lastly, a decrease and plateau in body mass was mirrored by an increase and plateau in voluntary wheel activity in the food restricted population. The data suggest that there is a tight biological link between hyperactivity and body mass and that adequate nutritional support might attenuate the drive for obligate exercise even before weight is fully restored.