Brain energy metabolism measured by (13)C magnetic resonance spectroscopy in vivo upon infusion of [3-(13)C]lactate
Duarte, João M N LU
; Girault, Freya-Merret
and Gruetter, Rolf
(2015)
In Journal of Neuroscience Research
93(7).
p.18-1009
- Abstract
The brain uses lactate produced by glycolysis as an energy source. How lactate originated from the blood stream is used to fuel brain metabolism is not clear. The current study measures brain metabolic fluxes and estimates the amount of pyruvate that becomes labeled in glial and neuronal compartments upon infusion of [3-(13)C]lactate. For that, labeling incorporation into carbons of glutamate and glutamine was measured by (13)C magnetic resonance spectroscopy at 14.1 T and analyzed with a two-compartment model of brain metabolism to estimate rates of mitochondrial oxidation, glial pyruvate carboxylation, and the glutamate-glutamine cycle as well as pyruvate fractional enrichments. Extracerebral lactate at supraphysiological levels... (More)
The brain uses lactate produced by glycolysis as an energy source. How lactate originated from the blood stream is used to fuel brain metabolism is not clear. The current study measures brain metabolic fluxes and estimates the amount of pyruvate that becomes labeled in glial and neuronal compartments upon infusion of [3-(13)C]lactate. For that, labeling incorporation into carbons of glutamate and glutamine was measured by (13)C magnetic resonance spectroscopy at 14.1 T and analyzed with a two-compartment model of brain metabolism to estimate rates of mitochondrial oxidation, glial pyruvate carboxylation, and the glutamate-glutamine cycle as well as pyruvate fractional enrichments. Extracerebral lactate at supraphysiological levels contributes at least two-fold more to replenish the neuronal than the glial pyruvate pools. The rates of mitochondrial oxidation in neurons and glia, pyruvate carboxylase, and glutamate-glutamine cycles were similar to those estimated by administration of (13)C-enriched glucose, the main fuel of brain energy metabolism. These results are in agreement with primary utilization of exogenous lactate in neurons rather than astrocytes.
(Less)
- author
- Duarte, João M N
LU
; Girault, Freya-Merret
and Gruetter, Rolf
- publishing date
- 2015-07
- type
- Contribution to journal
- publication status
- published
- keywords
- Animals, Blood Gas Analysis, Brain, Carbon Isotopes, Energy Metabolism, Glutamic Acid, Glutamine, Hydrogen-Ion Concentration, Lactic Acid, Magnetic Resonance Spectroscopy, Male, Radionuclide Imaging, Rats, Rats, Sprague-Dawley, Journal Article, Research Support, Non-U.S. Gov't
- in
- Journal of Neuroscience Research
- volume
- 93
- issue
- 7
- pages
- 10 pages
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- scopus:84929654459
- pmid:25522255
- ISSN
- 1097-4547
- DOI
- 10.1002/jnr.23531
- language
- English
- LU publication?
- no
- id
- 309049b0-3680-4add-9086-377189865f2d
- date added to LUP
- 2017-10-19 15:18:27
- date last changed
- 2024-01-29 04:52:00
@article{309049b0-3680-4add-9086-377189865f2d,
abstract = {{<p>The brain uses lactate produced by glycolysis as an energy source. How lactate originated from the blood stream is used to fuel brain metabolism is not clear. The current study measures brain metabolic fluxes and estimates the amount of pyruvate that becomes labeled in glial and neuronal compartments upon infusion of [3-(13)C]lactate. For that, labeling incorporation into carbons of glutamate and glutamine was measured by (13)C magnetic resonance spectroscopy at 14.1 T and analyzed with a two-compartment model of brain metabolism to estimate rates of mitochondrial oxidation, glial pyruvate carboxylation, and the glutamate-glutamine cycle as well as pyruvate fractional enrichments. Extracerebral lactate at supraphysiological levels contributes at least two-fold more to replenish the neuronal than the glial pyruvate pools. The rates of mitochondrial oxidation in neurons and glia, pyruvate carboxylase, and glutamate-glutamine cycles were similar to those estimated by administration of (13)C-enriched glucose, the main fuel of brain energy metabolism. These results are in agreement with primary utilization of exogenous lactate in neurons rather than astrocytes.</p>}},
author = {{Duarte, João M N and Girault, Freya-Merret and Gruetter, Rolf}},
issn = {{1097-4547}},
keywords = {{Animals; Blood Gas Analysis; Brain; Carbon Isotopes; Energy Metabolism; Glutamic Acid; Glutamine; Hydrogen-Ion Concentration; Lactic Acid; Magnetic Resonance Spectroscopy; Male; Radionuclide Imaging; Rats; Rats, Sprague-Dawley; Journal Article; Research Support, Non-U.S. Gov't}},
language = {{eng}},
number = {{7}},
pages = {{18--1009}},
publisher = {{John Wiley & Sons Inc.}},
series = {{Journal of Neuroscience Research}},
title = {{Brain energy metabolism measured by (13)C magnetic resonance spectroscopy in vivo upon infusion of [3-(13)C]lactate}},
url = {{http://dx.doi.org/10.1002/jnr.23531}},
doi = {{10.1002/jnr.23531}},
volume = {{93}},
year = {{2015}},
}