Avaliação da quantidade e regularidade de crises epilépticas induzidas por abrasamento elétrico da amigdala sobre a função cardiovascular em ratos com epilepsia
Carregando...
Data
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
Introduction: Temporal lobe epilepsy is one of the main neurological disorders,
characterized by the occurrence of generalized tonic-clonic seizures (GTCS).
These seizures significantly impact the quality of life of individuals with epilepsy
and are the main risk factor for Sudden Unexpected Death in Epilepsy (SUDEP).
Given this, it is relevant to investigate whether the randomness and number of
seizures should be considered in animal models of epilepsy with nonspontaneous seizures, aiming to adjust experimental protocols.
Methodology: Wistar rats with epilepsy induced by electrical amygdala kindling
were used and divided into five groups: Sham (control), CR10 (10 regular
seizures), CA10 (10 random seizures), CR20 (20 regular seizures), and CA20
(20 random seizures). The animals were subjected to their respective seizure
protocols, accompanied by ECG and EEG recordings. After the last day of
seizures, an ECG was recorded to evaluate heart rate variability (HRV).
Subsequently, the animals were euthanized, and the heart and aorta were used
in isolated organ protocols to assess cardiovascular function. The ventricle was
collected for histological analyses, and both the ventricle and brain were analyzed
for oxidative stress markers. Results: Epileptic animals exhibited ictal
bradycardia followed by tachycardia, along with alterations in autonomic
modulation, characterized by parasympathetic activity reduction, especially in
cases with a higher number of random seizures. The group with more seizures
showed a higher incidence of fibrillation, increased heart rate, and elevated
coronary flow during reperfusion. Interstitial fibrosis and cardiac hypertrophy were
also increased, with an interaction between seizure number and stimulation
regimen; hypertrophy was more pronounced in 20 regular seizures and 10
random seizures groups. Aortic relaxation function was impaired in animals with
10 seizures, regardless of the regimen. In cardiac tissue, there was a redox
imbalance, with decreased activity of the antioxidant enzyme SOD and increased
oxidative damage (carbonylated protein), varying depending on the seizure
regimen and number. In the hippocampus, oxidative stress markers (MDA and
carbonylated protein) were elevated, and antioxidant enzymes (SOD and CAT)
reduced; interestingly, a higher number of regular seizures was associated with
lower MDA levels, suggesting a conditioning effect. Conclusion: Epilepsy alone
significantly contributes to impaired cardiovascular function and increased
oxidative stress in both the hippocampus and cardiac tissue. Although seizure
randomness may exacerbate some of these changes, the predominant factors
appear to be epilepsy itself and the total number of seizures. Therefore, models
with regular seizures are also effective for evaluating epilepsy-related
cardiovascular alterations.
Descrição
Citação
LIMA JUNIOR, C. Q. Avaliação da quantidade e regularidade de crises epilépticas induzidas por abrasamento elétrico da amigdala sobre a função cardiovascular em ratos com epilepsia. 2025. 96 f. Tese (Doutorado em Multicêntrico em Ciências Fisiológicas) - Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, 2025.