Center for Metabolism
and Mitochondrial Medicine

Metabolism Unit

The mission of Metabolism Unit is to make available platform technologies, training, and study design and data analysis expertise for in vivo, ex vivo, and in vitro metabolic studies in rodent and cell culture models. The expertise of the unit extends from assessment of metabolic flux, energy expenditure, body composition, insulin sensitivity, exercise capacity, and insulin signaling in the whole animal, to the performance of metabolic, biochemical, and molecular studies in primary and immortal cell culture models of relevance to metabolic diseases.  The unit is based on the 11th floor of the Biomedical Science Tower.

Robert O'Doherty, PhD

Director

Michael Jurczak, PhD

Director of
Rodent Phenotyping

Platform Technologies

Mouse Metabolic Monitoring

The Comprehensive Lab Animal Monitor System (CLAMS) allows for the continuous and simultaneous monitoring of indirect calorimetry (VO2, respiratory exchange ratio), food intake, and physical activity in mice. The CLAMS is configured for eight individually housed test animals that comply with the USDHHS guidelines for long-term housing.  Data are exported in .csv format for use in multiple spread-sheet applications.

Mouse Body Composition

An EchoMRI body composition analysis system allows for measures of whole body fat, lean, free water, and total water mass in living, conscious animals. Results can be obtained from organs or mice (up to 130 g) in as little as 30 seconds.

Exercise Testing with CLAMS

Acute exercise testing in mice can be performed using a single-lane air-tight enclosed treadmill used in conjunction with the CLAMS for respiratory metabolic assessment during exercise. Integrated software allows for user-defined protocol interval and speed determination. The unit also features incline capability in 5° increments.

Exercise Testing in Open Air

Acute or chronic (training) exercise protocols can be performed in an open-air treadmill featuring three (rats) or six (mice) lanes, and includes adjustable incline capabilities (0-25°). User-friendly software allows for user-defined protocols, adjustable acceleration (in 0.1 meter/minute-steps per second), and wide range of speed (3-100 meters/minute). Data are exported in .csv format.

Bomb Calorimetry

The use of bomb calorimetry allows for the assessment of energy content in both food and/or feces to determine the energy intake of study animals. The Parr 6200 is an isoperibol oxygen bomb calorimeter that can analyze 8-9 samples per hour.

Mitochondrial Respiration

An OROBOROS O2k, fitted with two experimental chambers, is used for high-resolution respirometry and the quantitative assessment of oxygen flux in biological samples.. Multiple substrates-uncoupler-inhibitor titration (SUIT) protocols can be applied for the study of cell respiration or mitochondrial activity. The unit is also fitted with a fluorometer for the assessment of reactive oxygen species production. Typical protocols can be completed in 2-4 hours.

Insulin Sensitivity by Hyperinsulinemic Euglycemic Clamp

The hyperinsulinemic euglycemic clamp is the gold-standard for determining insulin sensitivity in vivo. By using metabolic isotopic tracers during clamp, whole-body and tissue-specific rates of carbohydrate and lipid metabolism can be measured under fasted and insulin-stimulated conditions in transgenic mice. Key parameters measured: basal rates of hepatic glucose production and whole-body glucose utilization; insulin-stimulated rates of hepatic glucose production and whole-body glucose uptake; tissue-specific rates of glucose uptake; fasting and insulin-stimulated plasma fatty-acid levels and palmitate turnover as indices of adipose tissue insulin sensitivity.

Staff

Nic Dedousis

nikolasd@pitt.edu
412-648-7009

Ian Sipula

ijsst2@pitt.edu
412-648-7009

Contact

Michael Jurczak, PhD | jurczakm@pitt.edu
Rob O’Doherty, PhD | rmo1@pitt.edu