Table 2. Glycogen contents, total glucose output (Δglucose output), changes in glycogen contents (Δglycogen content) and gluconeogenesis of livers from 24-hours fasted rats during substrate-free perfusion and perfusion with 5 mM L-glutamine.

Condition of the perfusion fluid	Perfusion time (minutes)	Control				Type 1 diabetes
		Glycogen content	ΔGlucose output	ΔGlycogen content	Gluconeo-genesis	Glycogen content	ΔGlucose output	ΔGlycogen content	Gluconeo-genesis
μmol glucosyl units per gram liver wet weight
Pre-perfusion	10	1.58±0.08 (n = 6)a,α,β	—	—	—	23.44±4.29 (n = 4)a,γ,δ	—	—	—
Substrate-free	100	1.22±0.02 (n = 3)α	9.60±0.31 (n = 3)c	-0.36	9.24	4.36±1.27 (n = 11)γ	19.14±2.29 (n = 10)c	-19.08	0.06
L-Glutamine (5 mM)	100	2.58±0.33 (n = 4)b, β	31.68±2.02 (n = 11)d	+1.00	32.68	11.96±0.96 (n = 12)b,δ	40.73±2.88 (n = 12)d	-11.48	29.25

^a,bp < 0.001;

^cp = 0.049;

^dp = 0.042;

^αp = 0.018;

^βp = 0.007;

^γp < 0.001;

^δp = 0.001.

The experiments were done according to the protocols illustrated by Fig 1 (glutamine infusion) and Fig 4 (substrate-free perfusion). For glycogen determination the livers were freeze-clamped in liquid nitrogen at 10 or 100 minutes perfusion time. Total glucose output (Δglucose output) was computed as the area under the corresponding curves in Figs 1A and 4A. Data are means ± SEM and the superscripts of each pair of values refer to the various p values given in the bottom (Student's t test); p values > 0.05 where omitted. Latin letters were used for comparing columns and Greek letters when comparing lines.