Simultaneous NMR microdialysis study of brain glucose metabolism in relation to fasting or exercise in the rat
- 1 June 2000
- journal article
- research article
- Published by American Physiological Society in Journal of Applied Physiology
- Vol. 88 (6), 1949-1954
- https://doi.org/10.1152/jappl.2000.88.6.1949
Abstract
To study the impact of exercise or fasting and of subsequent glucose supplementation on glucose metabolism in rats, a spectrophotometric method was used to determine peripheral blood glucose; a technique associating1H-NMR spectroscopy and cortical microdialysis was also used to observe intra- plus extracellular and extracellular brain glucose variations, respectively. Compared with control animals (204 ± 19 μM in dialysate, n = 10), exercise increased brain extracellular glucose levels to 274 ± 22 μM ( n = 8; P < 0.05), whereas fasting induced a drop in glucose levels down to 140 ± 9 μM ( n = 8; P < 0.05). After fasting, glucose supplemented by infusion increased glycemia from 7.4 ± 0.4 to 19.9 ± 0.8 mM ( n = 10; P < 0.001), as well as extracellular and extra- plus intracellular brain glucose to 263 ± 20% ( n = 8; P < 0.001) and 342 ± 28% ( n = 8; P < 0.001), respectively, over basal for that group. After exercise, a similar infusion increased glycemia from 7.3 ± 0.3 to 16.8 ± 1.1 mM ( n = 10; P < 0.001), as well as extracellular and extra- plus intracellular brain glucose to 178 ± 19% ( n = 8; P < 0.001) and 244 ± 20% ( n = 8; P < 0.001), respectively, over basal for that group. These results confirmed the existence of a link between glucose level variations in peripheral and cerebral areas but also showed that exercise increased extracellular brain glucose levels despite peripheral hypoglycemia, suggesting a specific regulation mechanism of cerebral glucose metabolism during exercise.Keywords
This publication has 29 references indexed in Scilit:
- Distribution of Glut1 Glucose Transporters in Different Brain Structures Compared to Glucose Utilization and Capillary Density of Adult Rat BrainsJournal of Cerebral Blood Flow & Metabolism, 1997
- Administration of a GABABAgonist Baclofen Before Running to Exhaustion in the Rat: Effects on Performance and on Some Indicators of FatigueInternational Journal of Sports Medicine, 1997
- Astrocytes and the delivery of glucose from plasma to neuronsNeurochemistry International, 1996
- Oxidation Rates, Complex Carbohydrates and ExerciseSports Medicine, 1995
- Effects of Changes in Rat Brain Glucose on Serotonergic and Noradrenergic NeuronsEuropean Journal of Neuroscience, 1995
- The Human Brain GLUT1 Glucose Transporter: Ultrastructural Localization to the Blood—Brain Barrier EndotheliaJournal of Cerebral Blood Flow & Metabolism, 1994
- in vivo identification and monitoring of changes in rat brain glucose by two‐dimensional shift‐correlated 1h nmr spectroscopyMagnetic Resonance in Medicine, 1992
- 2D COSY 1H NMR: a new tool for studying in situ brain metabolism in the living animalFEBS Letters, 1990
- Calibrated uncoupling of tightly coupled concentric surface coils forin vivo NMRMagnetic Resonance in Medicine, 1988
- Distribution of the Glucose Transporter in the Mammalian BrainJournal of Neurochemistry, 1986