The Metabolic Phenotyping Core provides state-of-the-art phenotypical measures to the scientific community at UMMC. Metabolic cages provide accurate measurements of whole metabolic information in rodents. Our metabolic capabilities offer access to Promethion metabolic screening (16 cages available), Columbus Instruments with environmental encloses (8 cages available), and AccuScan Instruments (8 cages) in vivo test to help advance the metabolic characterization of genetic and pharmacological research models of metabolic diseases, circadian rhythms and more. Metabolic cages equipped with oxygen sensors to measure oxygen consumption (VO2) and infrared beams to determine motor activity.
VO2 will be measured for 30 sec-2-min at 10-minute intervals continuously 24-hours a day using an oxygen sensor. Motor activity is determined using infrared light beams mounted in the cages in X, Y and Z axes. Sleep time using duration of immobility of 40s is also available for rodents. The very small movements of the body associated with breathing during sleep are ignored in these measurements.
The XYZ arrays consist of high resolution (1 cm pacing) infrared beam arrays that are invisible to the animal (wavelength ca. 900 nm). The intensity of these beams are measured in rapid succession and movements are easily detected and a centroid-algorithm calculates the animal position and movements. After the mice or rats are acclimatized to the new environment, data are generally recorded for approximately 4-6 days, depending on the needs of the investigators.
In addition, our core performs physiological and non-invasive metabolic experiments to assess insulin sensitivity (glucose tolerance tests, insulin tolerance test, hyperinsulinemic-euglycemic clamp) to assess in vivo insulin action, insulin signaling and glucose metabolism (using labeled isotopes) in awake mice and rats as well as hyperglycemic clamp experiments to assess in vivo pancreatic beta-cell function and its effects on glucose metabolism.