Figure 6.

Schematic rationale for the determination of R_a tracee using a stable isotope tracer method in a physiological steady state. Before (a) and throughout a tracer infusion (b, c and d), R_a tracee will be equal to R_d tracee, both of which are being constant in a steady state (d). To estimate R_a tracee, a tracer is primed continuously infused intravenously. At the beginning of the infusion, rate of removal of tracer from the compartment (b and c) is lower than tracer infusion rate (F). However, it will be eventually equal over time to F (d). Red and black circles represent tracee and tracer, respectively. For simplicity, naturally occurring heavier glucose molecules were ignored.