A Comparison of Oxidative Lactate Metabolism in Traumatically Injured and Control Brains

作者：Jalloh Ibrahim^*; Helmy Adel; Howe Duncan J; Shannon Richard J; Grice Peter; Mason Andrew; Gallagher Clare N; Murphy Michael P; Pickard John D; Menon David K; Carpenter T Adrian; Hutchinson Peter J; Carpenter Keri L H^*

来源：Journal of Neurotrauma, 2018, 35(17): 2025-2035.

DOI：10.1089/neu.2017.5459

• brain metabolism
• microdialysis
• NMR
• 3-C-13 lactate
• traumatic brain injury (human)

Metabolic abnormalities occur after traumatic brain injury (TBI). Glucose is conventionally regarded as the major energy substrate, although lactate can also be an energy source. We compared 3-C-13 lactate metabolism in TBI with "normal" control brain and muscle, measuring C-13-glutamine enrichment to assess tricarboxylic acid (TCA) cycle metabolism. Microdialysis catheters in brains of nine patients with severe TBI, five non-TBI brain surgical patients, and five resting muscle (non-TBI) patients were perfused (24h in brain, 8h in muscle) with 8mmol/L sodium 3-C-13 lactate. Microdialysate analysis employed ISCUS and nuclear magnetic resonance. In TBI, with 3-C-13 lactate perfusion, microdialysate glucose concentration increased nonsignificantly (mean +11.9%, p=0.463), with significant increases (p=0.028) for lactate (+174%), pyruvate (+35.8%), and lactate/pyruvate ratio (+101.8%). Microdialysate C-13-glutamine fractional enrichments (median, interquartile range) were: for C4 5.1 (0-11.1) % in TBI and 5.7 (4.6-6.8) % in control brain, for C3 0 (0-5.0) % in TBI and 0 (0-0) % in control brain, and for C2 2.9 (0-5.7) % in TBI and 1.8 (0-3.4) % in control brain. C-13-enrichments were not statistically different between TBI and control brain, showing both metabolize 3-C-13 lactate via TCA cycle, in contrast to muscle. Several patients with TBI exhibited C-13-glutamine enrichment above the non-TBI control range, suggesting lactate oxidative metabolism as a TBI "emergency option."

• 出版日期2018-9