Table 2. Metabolism of 5 and 1 mmol/L [3-¹³C]glutamine in brain slices of wild-type (WT) and glutaminase-deficient (GLS1+/−) mice (nuclear magnetic resonance (NMR) data).

Experimental condition	Metabolite removal (−) or production (in μmol/g dry weight per hour)
	Glutamate				Glutamine		Aspartate				Succinate	GABA	13 CO 2
	C-2	C-3	C-4	C-5	C-2	C-3	C-1	C-2	C-3	C-4	C-2+C-3	C-3
5 mmol/L [3- 13 C]glutamine
WT mice (n=8)	0.9±0.2	9.4±1.4	0.1±0.05	0.2±0.1	1.6±0.2	−95.8±5.7	2.4±0.2	8.9±0.8	8.7±0.7	1.9±0.2	0.5±0.2	1.6±0.1	59.6±4.5
GLS1+/− mice (n=8)	0.8±0.2	5.2±0.7a	0.1±0.05	0.2±0.1	1.5±0.2	−75.3±4.7a	2.5±0.2	7.7±0.6	7.5±0.6	1.7±0.2	0.6±0.2	1.3±0.1	46.2±3.9a
1 mmol/L [3- 13 C]glutamine
WT mice (n=8)	0.4±0.1	2.2±0.3	—	—	0.3±0.1	−30.4±0.8	0.9±0.1	3.9±0.2	3.8±0.2	0.7±0.1	—	0.9±0.1	17.3±0.7
GLS1+/− mice (n=8)	0.2±0.1	0.9±0.1a	—	—	0.2±0.1	−22.8±0.9a	0.8±0.1	3.2±0.2	3.0±0.2	0.6±0.1	—	0.7±0.1	13.2±0.9a

Brain slices were incubated for 1 hour with 5 or 1 mmol/L [3-¹³C]glutamine. The slice dry weight was 122±3 mg (WT mice) and 119±5 mg (GLS1+/− mice) with 5 mmol/L [3-¹³C]glutamine, and 123±4 mg (WT mice) and 130±2 mg (GLS1+/− mice) with 1 mmol/L [3-¹³C]glutamine. Results (in μmol/g dry weight/hour) are presented as mean values±s.e.m. for eight experiments (n=8). Statistical difference was measured by the unpaired Student's t-test and P<0.05 was considered statistically significant. The corresponding enzymatic data are reported in Table 1.

^aDifferent from WT mice.