Measurement of glucose homeostasis in vivo: combination of tracers and clamp techniques.

A tracer technique referred to as "pancreatic-blood glucose clamp" allows assessment in response to a change in blood glucose, insulin, and/or glucagon of whole body glucose disposal, endogenous glucose production, specific tissue/organ glucose uptake and storage, and insulin secretion. This technique is currently considered the optimal method for measurement of insulin sensitivity and glucose effectiveness. We describe here, for use in conscious-unrestrained mice and rats, the pancreatic-blood glucose clamp technique and its associated methods; which include catheterization of blood vessels; a clamp of plasma insulin, glucagon, and glucose; analyses of metabolites and tracers; and calculations.