Expression of cardiac inwardly rectifying potassium channels in pentylenetetrazole kindling model of epilepsy in rats

Abstract

Clinical and experimental studies show that epilepsy affects cardiac function; however, the underlying molecular mechanism has not been fully elucidated. Inwardly-rectifying potassium (Kir) channels transport K+ ions into excitable cells such as neurons and cardiomyocytes; they control the cell excitability by acting towards the repolarization phase of cardiac action potential. Kir channel expression has been previously shown to vary in epileptic brains, at the same time seizures are known to affect the autonomic nervous system. Kir channel expression in cardiac tissue is a possible mechanism for the explanation of cardiac pathology in epilepsy. We investigate the expression of Kir channels in epileptic cardiac tissue by using pentylenetetrazole (PTZ)-kindling model in rats. Our molecular analyses showed significant decrease in cardiac Kir channel mRNA and protein expression of PTZ-kindled rats. Interestingly, both Kir2.x, which directs IK1 flux in ventricular tissue and Kir3.x, which is responsible for IKACh in the atria, were observed to decrease significantly. Kir channel expression also differs between females and males. This is the first study to our knowledge in epileptic cardiac tissue showing the expression of Kir channels. Our results show that Kir channels may play a role in cardiac pathology associated with epilepsy.

Investigating Cardiac Morphological Alterations in a Pentylenetetrazol-Kindling Model of Epilepsy

“…We can speculate that multiple and recurrent seizures cause accumulated damage in cardiac tissue which in turn has the potential to interfere with electrical conduction in the heart, leading thus to SUDEP during a typical tonic-clonic seizure. Hemorrhage results in a diminished return of venous blood to the heart, inducing a lowering of blood pressure as already demonstrated by our previous study conducted in the same in vivo model during an ictal seizure [16]. However, our results may be eventually attributed to a secondary toxic effect on myocardium related to PTZ exposure.…”

“…An impairment of the autonomic nervous system in the regulation of CV functions during seizures has been recently reported by our previous study performed in a PTZ-kindled rat model, showing aberrant blood pressure and electrocardiographic (ECG) recordings [16]. We suggested that this data may be related to an altered expression of inwardly rectifying potassium (Kir) channels in the heart [17].…”

Unraveling the Role of Inwardly Rectifying Potassium Channels in the Hippocampus of an Aβ(1–42)-Infused Rat Model of Alzheimer’s Disease

“…Functional and expression alterations of K + channels cause disruptions in neuronal balance and membrane excitability, contributing to the development and progress of several neurological diseases, including AD [8][9][10][11][12]. Among them, Kir channels have the ability to mediate the inward flow of K + ions at hyperpolarizing membrane voltages more readily than the outward flow of K + at depolarizing voltages [13].…”

“…Despite its prevalence, the AD pathogenesis is not completely understood, and, currently, there are no effective treatments to slow or halt the progression of its symptoms [7]. Emerging evidence points out a key role of ion channels in the progress and development of a variety of neurological disorders, including epilepsy [8,9], autism spectrum disorders [10], multiple sclerosis [11], and AD [12]. Among them, the inwardly rectifying potassium (K + ) channels (Kir) are essential for maintaining the resting membrane potential and controlling the cell excitability by the regulation intracellular and extracellular flow of K + ions in different types of cells, including neurons.…”

Cornus Mas L improves Antioxidant Status in the Liver, Lung, Kidney, Testis and Brain of Ehrlich Ascites Tumor Bearing Mice

“…An increase in the tumor-related ROS production in the tissues causes various side effects due to its cytotoxic and genotoxic effects. As a result, research has been conducted on the protective effects of a series of antioxidant substances on it providing protection against cancer (Alavian et al, 2014;Akyüz et al, 2018;Jia-Fu et al, 2012;Reinert et al 2013;Zarei et al 2014). In this study, for the first time, to the best of our knowledge, an examination of the protective effect of C. mas L. fruit extract on tissues of oxidant and antioxidant parameters such as various enzyme activities, GSH, GSSG, TOS OSI, and TAS, which have been altered in relation to cancer in tissues of tumor induced Balb/C mice.…”