Cardiovascular changes in genetic absence epileptic WAG/Rij rats: Effects of chronic ethosuximide treatment

Abstract

Purpose: The aim of this study was to investigate the effects of chronic ethosuximide (ETX) treatment on absence seizures and cardiovascular parameters in WAG/Rij rats with genetic absence epilepsy.Materials and Methods: Eight-weeks old, male Wistar and WAG/Rij rats were divided into four groups (n=20): Wistar control, Wistar ETX, WAG/Rij control and WAG/Rij ETX. ETX groups received chronic ETX treatment (oral, 300 mg/kg/day) for 3 months. At the end of the 3-month-treatment period; the total and mean duration, also number of spike wave discharges (SWDs) were evaluated using EEG recordings. Mean arterial blood pressure (MAP) and heart rate (HR) measurements were performed. Results: ETX treatment significantly decreased the duration and frequency of SWDs in WAG/Rij rats. MAP in WAG/Rij control group was markedly higher than Wistar control group. In Wistar ETX group, HR was significantly slower than Wistar control group. KCl-induced contraction response enhanced in Wistar ETX group and diminished in WAG/Rij control group compared to Wistar control group. Conclusion: Increased MAP and vascular reactivity in WAG/Rij rats. ETX treatment did not alter cardiovascular parameters in WAG/Rij rats whereas the treatment decreased the HR and vascular reactivity without affecting MAP in Wistar rats. T-type Ca++ channels may play a role in these changes.