For a tracer to be valid it must follow the metabolism of the tracee without distortion. Especially when the tracer contains several deuterium substitutions, the tracer can be altered or degraded differently from the metabolite it is to trace or be subject to distorting isotope effects. To determine whether2H5-glycerol is a valid tracer for following glycerol kinetics,2H5-glycerol and [2-13C] glycerol tracers were infused simultaneously in six healthy postabsorptive adult subjects. After 90 min of tracer infusion, epinephrine was also infused for 60 min to stimulate lipolysis and increase glycerol flux. Glycerol flux increased from 2.2±0.3 to 6.7±0.4 μmol/kg per minute (with the13C tracer) and from 2.2±0.3 to 6.7±0.3 μmol/kg per minute (with the2H tracer) when epinephrine was infused. There was no significant difference in glycerol flux measured with the2H tracer compared to the13C tracer either under basal or a stimulated flux condition. These results indicate that2H5-glycerol is a valid tracer for measuring glycerol metabolism in humans.
- Glycerol kinetics
- Stable isotope tracers
ASJC Scopus subject areas
- Internal Medicine
- Endocrinology, Diabetes and Metabolism