1. Glucose kinetics were assessed in seven normal adult male subjects by an intravenous bolus technique with the use of a non-radioactive isotopically labelled preparation, [6,6-2H]glucose, as tracer. Tracer enrichment in plasma was assessed by gas chromatography-mass spectrometry. For comparison five subjects also received a simultaneous intravenous bolus of [6-3H]glucose and kinetics were assessed by conventional means.
2. Administration of [6,6-2H]glucose did not alter circulating glucose or insulin concentrations.
3. Glucose turnover, assessed by the use of [6,6-2H]glucose, was 11·4 (±0·9) μmol min−1 kg−1 and 11·6 (±0·5) μmol min−1 kg−1 with [6-3H]glucose. The mean metabolic clearance rate of glucose was 2·3 (±0·3) ml min−1 kg−1 with both isotopically labelled tracers. Estimates of mean residence time, glucose pool and glucose space were also similar by each technique.
4. [6,6-2H]Glucose is therefore an effective tracer and allows investigation of glucose kinetics without administration of a radioactive label.