FIG. 1.

A: Intraportal glucose infusion clamp. Basal and clamp SS indicate the steady state during the basal and clamp period, respectively. Porcine insulin was infused at either 0.75 (studies 1 and 2) or 0.15 mU · kg⁻¹ · min⁻¹ (study 3) to achieve postprandial hyperinsulinemia or maintain basal insulin levels. Exogenous glucose was given into portal vein to achieve systemic hyperglycemia (studies 1 and 3) or maintain systemic euglycemia (study 2). B: Calculation of NHGA. Glucose label indicates the constant and the variable tracer infusions.