Fig. 4. The cumulative absorption (inset plots) and apparent rates of absorption of [³H]3OMD-glucose and [¹⁴C]L-glucose as a function of time since gavage of the probes to house sparrows. (A) Measurements made under relatively nonsaturating conditions (200 mmol l^-1 mannitol in the gavage solution, N=7 birds); (B) measurements made under more saturating conditions (i.e. 200 mmol l^-1 3OMD-glucose replaced mannitol in the gavage solution, N=6). Filled symbols and solid lines, [¹⁴C]L-glucose; unfilled symbols and dashed lines, [³H]3OMD-glucose. The absorption of 3OMD-glucose was slightly but significantly higher than that of L-glucose. The asterisk in A designates the significantly higher apparent absorption rate of [³H]3OMD-glucose (P=0.015) than of [¹⁴C]L-glucose at the 15 min sampling point.