METABOLIC PHYSIOLOGY AND ENERGY BALANCE CORE Project Summary/Abstract The main function of the Metabolic Physiology and Energy Balance Core is to perform experimental services to investigate alterations of glucose homeostasis, insulin sensitivity, lipid metabolism and body composition in rodent models of obesity and insulin resistance. Increasingly, the biologic roles of gene products and pathways emerging from genomic, proteomic, metabolomic and other discovery approaches are being queried by generating overexpression, gene knockout or knock-in of altered genes in rodent models. Thus, there is a growing need for characterization of new mouse models created by genetic or viral vector technologies. The Metabolic Physiology and Energy Balance Core is designed to meet the needs for characterization of rodent models that have alterations in glucose homeostasis, insulin action, and/or body composition and adiposity. The specific objectives of the Core are to carry out and interpret experiments for Core users aimed at investigating glucose homeostasis and energy balance. In vivo studies in awake mice include continuous glucose monitoring, measuring metabolic rates and energy balance by indirect calorimetry and body composition by EchoMRI and DEXA. Studies in primary adipocytes or adipose explants include glucose transport, metabolism, and lipolysis with assessment of insulin sensitivity. Services also include the differentiation of stromovascular cells into adipocytes and assessment of glucose uptake and insulin sensitivity. There is high demand for these services and we anticipate high utilization. The Core is actively utilized by BADERC members and other investigators in the Boston area. It enables investigators from other fields to carry out studies in the area of diabetes and metabolism that may not otherwise be feasible. Since the inception of the Core, we have received an increasing number of requests for services from investigators new to the field of metabolism, diabetes and obesity. The Core provides critical support for NIH grants for both new and established investigators. In many cases, the Core provides the tools that enable experts in other fields to apply their sophisticated techniques to metabolism research.