Fig. 3. Plots, and semi-log inset plots, of plasma [³H]3OMD-glucose and [¹⁴C]L-glucose concentration as a function of time since injecting the probes. The units for concentration are proportion per gram plasma, because values of d.p.m. g^-1 plasma were normalized to d.p.m. dose for each individual. (A) Measurements made under relatively nonsaturating conditions (200 mmol l^-1 mannitol in the gavage solution, N=6 birds); (B) measurements made under more saturating conditions (i.e. 200 mmol l^-1 3OMD-glucose replaced mannitol in the gavage solution, N=4). Filled symbols and solid lines, [¹⁴C]L-glucose; unfilled symbols and broken lines, [³H]3OMD-glucose.