Alterations in aortic vasorelaxation in rats with epilepsy induced by the electrical amygdala kindling model

Cardiovascular alterations are frequently related to epilepsy in both clinical and experimental models, and have been hypothesized as a potential contributor to sudden unexpected death in epilepsy (SUDEP). Further, the frequency of generalized tonic-clonic seizures (GTCS) is a primary risk factor for SUDEP. Therefore, we aimed to evaluate the vascular response of rats subjected to the electrical amygdala kindling model of epilepsy. Male Wistar rats were randomly distributed into the following groups: without seizures (sham, n = 8), 5 GTCS (5 S, n = 5), and 10 GTCS (10 S, n = 6). One day after the last seizure, the rats were euthanized, and the thoracic aorta rings with (E⁺) and without (E^-) endothelium were used to evaluate vascular reactivity ex vivo using the organ bath system. The maximum response to acetylcholine-induced vasorelaxation in the E⁺ aortic ring was lower in the 5 S group than in the sham and 10 S groups. A reduced concentration of sodium nitroprusside was required to induce vasorelaxation in the E^- aortic rings. These results suggest an impairment in endothelial function and alterations in the nitric oxide (NO) pathway. In conclusion, epilepsy altered the vasorelaxation of the aortic rings and the number of seizures influenced these alterations; therefore, an analysis of endothelial function in patients with a high risk of SUDEP may be beneficial.