| Autor(es): |
Porto Dechandt, Carlos Roberto
[1]
;
Ferrari, Gustavo Duarte
[1]
;
dos Santos, Jonathas Rodrigo
[1]
;
Cortes de Oliveira, Jose Antonio
[2]
;
Patricio Silva-Jr, Rui Milton
;
Siqueira Cunha, Alexandra Olimpio
[3]
;
Garcia-Cairasco, Norberto
[3]
;
Alberici, Luciane Carla
[1]
Número total de Autores: 8
|
| Afiliação do(s) autor(es): | [1] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Dept Fis & Quim, Ribeirao Preto - Brazil
[2] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Fisiol, Ribeirao Preto - Brazil
[3] Patricio Silva-Jr, Jr., Rui Milton, Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Fisiol, Ribeirao Preto - Brazil
Número total de Afiliações: 3
|
The Wistar Audiogenic Rat (WAR) strain is a genetic model of epilepsy, specifically brainstem-dependent tonic-clonic seizures, triggered by acute auditory stimulation. Chronic audiogenic seizures (audiogenic kindling) mimic temporal lobe epilepsy, with significant participation of the hippocampus, amygdala, and cortex. The objective of the present study was to characterize the mitochondrial energy metabolism in hippocampus and cortex of WAR and verify its relationship with seizure severity. Hippocampus of WAR naive (no seizures) presented higher oxygen consumption in respiratory states related to the maximum capacities of phosphorylation and electron transfer system, elevated mitochondrial density, lower GSH/GSSG and catalase activity, and higher protein carbonyl and lactate contents, compared with their Wistar counterparts. Audiogenic kindling had no adding functional effect in WAR, but in Wistar, it induced the same alterations observed in the audiogenic strain. In the cortex, WAR naive presented elevated mitochondrial density, lower GSH/GSSG and catalase activity, and higher protein carbonyl levels. Chronic acoustic stimulation in Wistar induced the same alterations in cortex and hippocampus. Mainly in the hippocampus, WAR naive presented elevated mRNA expression of glucose, lactate and excitatory amino acids transporters, several glycolytic enzymes, lactate dehydrogenase, and Na+/K+ ATPase in neurons and in astrocytes. In vivo treatment with mitochondrial uncoupler 2,4-dinitrophenol (DNP) or N-acetylcysteine (NAC) in WAR had no effect on mitochondrial metabolism, but lowered oxidative stress. Unlike DNP, NAC downregulated all enzyme genes involved in glucose and lactate uptake, and metabolism in neurons and astrocytes. Additionally, it was able to reduce brainstem seizure severity in WAR. In conclusion, in WAR naive animals, both cerebral cortex and hippocampus display elevated mitochondrial density and/or activity associated with oxidative damage, glucose and lactate metabolism pathways upregulation, and increased Na+/K+ ATPase mRNA expression. Only in vivo treatment with NAC was able to reduce seizure severity of kindled WARs, possibly via down regulation of glucose/lactate metabolism. Taken together, our results are a clear contribution to the field of mitochondrial metabolism associated to epileptic seizures. (AU) |