Controle hidroeletrolítico e respostas cardiovasculares à injeção central de angII, carbacol e hiperosmolaridade plasmática em ratos com epilepsia induzida por pilocarpina
Nenhuma Miniatura disponível
Data
2019-11-29
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
Status epilepticus (SE) is a condition caused by failure of the mechanisms responsible for the
termination of the seizure or the onset of the mechanism leading to abnormally prolonged
seizures. An epileptic seizure is defined as “the transient occurrence of signs and/or secondary
symptoms of abnormal brain neuronal activity”. Epilepsy is a brain syndrome defined by at
least one of the following conditions: (1) less than 2 unprovoked epileptic seizures within 24
hours; (2) an unprovoked seizure in individuals who have factors associated with a higher
likelihood of having a decreased epileptic threshold; (3) diagnosis of epilepsy syndrome.
Individuals with epilepsy are more likely to suffer sudden death, with sudden and unexpected
death in epilepsy (SUDEP) a more common category. The pilocarpine-induced epilepsy (PIE)
model was the most used to study temporal lobe epilepsy (TLE). The renin angiotensin system
(RAS) is known to be involved in some neurodegenerative diseases as well as epilepsy. And, it
has been shown that the central nervous system (CNS) areas are responsible for thirst
behavior and appetite for waste affected by the epilepsy model. Thus, this study aimed to
study cardiovascular control in the face of changes in central levels of angiotensin II (Ang II),
carbachol and plasma osmolarity in the PIE model. We used Wistar rats (250-280 g), preused with methylscopolamine (1mg / kg intraperitoneal -ip), after receiving a pilocarpine
injection (350 mg / kg-ip) to induce SE. After 3 hours of SE, dizepam (10 mg / kg -i.p.) was
injected to stop a seizure. Daily intake of water and 1,8% NaCl, no difference between
groups, and body weight were made in which epilepsy group uses a lower weight gain when
using a control group (358 ± 13 vs. 406 ± 6 g, respectively). Animals prepared with cannulae
directed to the lateral ventricle (VL) were divided into two groups with which cardiovascular
records were recorded: one group that removes intracerebroventricular (icv) injection from
Ang II and the other one with carbachol. We observed that the pressor response was higher in
the epilepsy group when compared to the control after Ang II injection (Epilepsy: 28,0 ± 3,3
vs. Control: 13,3 ± 0,7 mmHg, p <0,05). , a variation in heart rate (ΔHR) was not different
between groups. In animals receiving icv carbacol injection, the response was not different
between groups, but there was a difference between groups compared with baseline (-0,5 ±
1,4 vs. 22,3 ± 4,6 mmHg, epilepsy and 1,0 ± 2,3 vs. 24,3 ± 4,0 mmHg, control, p <0,05),
ΔHR was different between groups (Epilepsy: -24,3 ± 6,1 vs. Control: - 56,3 ± 13,2 bpm), as
well as within the control group, comparing their baseline period to the post-carbachol
injection period (396,7 ± 17,0 vs. -56,3 ± 13,2 bpm, respectively). In another experiment,
the animals were recorded after an intrinsic 12% NaCl overload, which showed a pressure
drop at 30, 40 and 50 min in the epilepsy group when compared to 10 minutes after gavage (
10 ': 5,6 ± 2,9 vs. 30': -8,0 ± 5,3 mmHg; 40 ': -11,5 ± 4,9 mmHg; 50': -9,0 ± 4,5 mmHg ).
This was not observed in control animals. Regarding HR there was no difference between the
groups, but no group with epilepsy increased after gavage when comparing the times -10, -1,
40, 50 and 60 minutes (10 ': 49,2 ± 23,0 vs. -10 ': 0,0 ± 0,0 bpm; -1': -5,7 ± 11,1 bpm; 40
': 3,5 ± 7,3 bpm; 50': -7,0 ± 9,6 bpm and 60 ': -5,7 ± 11,3 bpm). Our results suggest that
pilocarpine-induced epilepsy is capable of altering angiotensin, carbachol-dependent
mechanisms and increased plasma osmolarity, which alter or control harmful blood pressure
or corrective substance use and contribute to SUDEP.
Descrição
Palavras-chave
Epilepsia do lobo temporal , Pilocarpina , Status epilepticus , Sistema renina angiotensina , Angiotensina II , Carbacol , Gavagem , Pressão arterial , Frequência cardíaca , Temporal lobe epilepsy , Pilocarpine , Status epilepticus , Renin system angiotensin , Angiotensin II , Carbachol , Gavage , Blood pressure , Heart rate
Citação
MERCÊS, T. M. Controle hidroeletrolítico e respostas cardiovasculares à injeção central de angII, carbacol e hiperosmolaridade plasmática em ratos com epilepsia induzida por pilocarpina. 2019. 58 f. Dissertação (Mestrado em Ciências Fisiológicas) - Universidade Federal de Goiás, Goiânia, 2019.