Mouse Metabolic Phenotyping Center

The hyperinsulinemic clamp is used to measure insulin action in vivo. Hyperinsulinemic clamps are performed on conscious mice with catheters chronically implanted in the jugular vein and carotid artery. A continuous infusion of insulin is given. Glucose levels are monitored in arterial samples every 5-10 min using a  glucose analyzer that allows the analysis of glucose with less than 1 µl of blood. Glucose is infused in the jugular vein catheter at rates necessary to achieve the desired glucose level, based on feedback from arterial glucose measurements. These methods allow assessment of the responsiveness of the body to insulin (Halseth et al. Am. J. Physiol. 1999 and Ayala et al. Diabetes 2006). By combining this technique with the tracer method one can also examine the impact of insulin on suppression of endogenous glucose production