Year: 2010
Type: article
Abstract: OBJECTIVE: Analysis of energy expenditure (EE) in mice is essential to obesity research. Since EE varies with body mass, comparisons between lean and obese mice are confounded unless EE is normalized to account for body mass differences. We 1) assessed the validity of ratio-based EE normalization involving division of EE by either total body mass (TBM) or lean body mass (LBM), 2) compared the independent contributions of LBM and fat mass (FM) to EE, and 3) investigated whether leptin contributes to the link between FM and EE. RESEARCH DESIGN AND METHODS: We used regression modeling of calorimetry and body composition data in 137 mice to estimate the independent contributions of LBM and FM to EE. Subcutaneous administration of leptin or vehicle to 28 obese ob/ob mice and 32 fasting wild-type mice was used to determine if FM affects EE via a leptin-dependent mechanism. RESULTS: Division of EE by either TBM or LBM is confounded by body mass variation. The contribution of FM to EE is comparable to that of LBM in normal mice (expressed per gram of tissue) but is absent in leptin-deficient ob/ob mice. When leptin is administered at physiological doses, the plasma leptin concentration supplants FM as an independent determinant of EE in both ob/ob mice and normal mice rendered leptin-deficient by fasting. CONCLUSIONS: The contribution of FM to EE is substantially greater than predicted from the metabolic cost of adipose tissue per se, and the mechanism underlying this effect is leptin dependent. Regression-based approaches that account for variation in both FM and LBM are recommended for normalization of EE in mice.
Source: Diabetes
DOI: 10.2337/db09-1582
Institution: University of Washington
Language: English
Subfield: Endocrine and Autonomic Systems
Field: Neuroscience
Domain: Life Sciences
Open Access status: hybrid
Awards: Peripheral and Central Inflammatory Signals in the Sickness Response, G1153718808, G1228426491, G154697889, G1948980911, G2057822194, MMPC: Diabetes and Diabectic Complications, G234089594, G2519283761, Drug-Induced Allostasis and Its Motivational Effects During Adolescence, Neuroendocrine Control of Energy Balance and Insulin Sensitivity, G3822281516, Coordinating and Bioinformatics Unit for the MMPC/DiaComp, Hypothalamic Control of Food Intake and Body Weight, Hypothalamic Inflammation and Energy Homeostasis, G9000024636, G9000146489, G9000324950, Nutrition Obesity Research Center, Diabetes Research Center, Divergent Mechanisms Underlying Anorexic and Antidiabetic Actions of FGF1 in the Brain
OpenAlex ID: W2096114331