TY - JOUR
T1 - Alterations of Brain Energy Metabolism in Type 2 Diabetic Goto-Kakizaki Rats Measured In Vivo by (13)C Magnetic Resonance Spectroscopy
AU - Girault, Freya-Merret
AU - Sonnay, Sarah
AU - Gruetter, Rolf
AU - Duarte, João M N
PY - 2019
Y1 - 2019
N2 - Type 2 diabetes (T2D) is associated with deterioration of brain structure and function. Here, we tested the hypothesis that T2D induces a reorganization of the brain metabolic networks that support brain function. For that, alterations of neuronal and glial energy metabolism were investigated in a T2D model, the Goto-Kakizaki (GK) rat. (13)C magnetic resonance spectroscopy in vivo at 14.1 T was used to detect (13)C labeling incorporation into carbons of glutamate, glutamine, and aspartate in the brain of GK (n = 7) and Wistar (n = 13) rats during intravenous [1,6-(13)C]glucose administration. Labeling of brain glucose and amino acids over time was analyzed with a two-compartment mathematical model of brain energy metabolism to determine the rates of metabolic pathways in neurons and glia. Compared to controls, GK rats displayed lower rates of brain glutamine synthesis (- 32%, P < 0.001) and glutamate-glutamine cycle (- 40%, P < 0.001), and mitochondrial tricarboxylic acid (TCA) cycle rate in neurons (- 7%, P = 0.036). In contrast, the TCA cycle rate of astrocytes was larger in GK rats than controls (+ 21%, P = 0.042). We conclude that T2D alters brain energy metabolism and impairs the glutamate-glutamine cycle between neurons and astrocytes, in line with diabetes-induced neurodegeneration and astrogliosis underlying brain dysfunction.
AB - Type 2 diabetes (T2D) is associated with deterioration of brain structure and function. Here, we tested the hypothesis that T2D induces a reorganization of the brain metabolic networks that support brain function. For that, alterations of neuronal and glial energy metabolism were investigated in a T2D model, the Goto-Kakizaki (GK) rat. (13)C magnetic resonance spectroscopy in vivo at 14.1 T was used to detect (13)C labeling incorporation into carbons of glutamate, glutamine, and aspartate in the brain of GK (n = 7) and Wistar (n = 13) rats during intravenous [1,6-(13)C]glucose administration. Labeling of brain glucose and amino acids over time was analyzed with a two-compartment mathematical model of brain energy metabolism to determine the rates of metabolic pathways in neurons and glia. Compared to controls, GK rats displayed lower rates of brain glutamine synthesis (- 32%, P < 0.001) and glutamate-glutamine cycle (- 40%, P < 0.001), and mitochondrial tricarboxylic acid (TCA) cycle rate in neurons (- 7%, P = 0.036). In contrast, the TCA cycle rate of astrocytes was larger in GK rats than controls (+ 21%, P = 0.042). We conclude that T2D alters brain energy metabolism and impairs the glutamate-glutamine cycle between neurons and astrocytes, in line with diabetes-induced neurodegeneration and astrogliosis underlying brain dysfunction.
KW - Journal Article
U2 - 10.1007/s12640-017-9821-y
DO - 10.1007/s12640-017-9821-y
M3 - Article
C2 - 28971314
SN - 1029-8428
VL - 36
SP - 268
EP - 278
JO - Neurotoxicity Research
JF - Neurotoxicity Research
IS - 2
ER -