Table 4.

Linear correlation for total or ¹³C-labeled concentrations between pairs of glycolytic- and Krebs cycle-derived metabolites in human lung tissues^A

	R2
PlotsB	Non-cancerous	Cancer
[Ala] versus [succinate]	0.025	0.761
[13C-Ala] versus [13C-succinate]	0.483	0.792
[lactate] versus [succinate]	0.056	0.395
[13C-lactate] versus [13C-succinate]	0.412	0.374
[Glu] versus [succinate]	0.018	0.343
[13C-Glu] versus [13C-succinate]	0.072	0.912
[citrate] versus [succinate]	0.061	0.133
[13C-citrate] versus [13C-succinate]	0.069	0.789

^A R² for the linear regression fit was calculated using Excel for patients #6–10 (n = 5).

^B Obtained from GC-MS analysis; [metabolite]: total concentration in μmole/g dry weight of metabolite; [¹³C-metabolite]: μmole/g dry weight of ¹³C-labeled metabolites