Low Frequency Electromagnetic Field Conditioning Protects against I/R Injury and Contractile Dysfunction in the Isolated Rat Heart

Abstract

Low frequency electromagnetic field (LF-EMF) decreases the formation of reactive oxygen species, which are key mediators of ischemia/reperfusion (I/R) injury. Therefore, we hypothesized that the LF-EMF protects contractility of hearts subjected to I/R injury. Isolated rat hearts were subjected to 20 min of global no-flow ischemia, followed by 30 min reperfusion, in the presence or absence of LF-EMF. Coronary flow, heart rate, left ventricular developed pressure (LVDP), and rate pressure product (RPP) were determined for evaluation of heart mechanical function. The activity of cardiac matrix metalloproteinase-2 (MMP-2) and the contents of coronary effluent troponin I (TnI) and interleukin-6 (IL-6) were measured as markers of heart injury. LF-EMF prevented decreased RPP in I/R hearts, while having no effect on coronary flow. In addition, hearts subjected to I/R exhibited significantly increased LVDP when subjected to LF-EMF. Although TnI and IL-6 levels were increased in I/R hearts, their levels returned to baseline aerobic levels in I/R hearts subjected to LF-EMF. The reduced activity of MMP-2 in I/R hearts was reversed in hearts subjected to LF-EMF. The data presented here indicate that acute exposure to LF-EMF protects mechanical function of I/R hearts and reduces I/R injury.

Low frequency electromagnetic field decreases ischemia–reperfusion injury of human cardiomyocytes and supports their metabolic function

“…Continuing the hypothesis that electromagnetic field may be used as a therapeutic agent 26,27 and following the study of Ma et al, 25 who demonstrated the inhibition of ROS generation by LF-EMF, we showed the cardioprotective role of LF-EMF in ex vivo model of cardiac I/R. 18 Cardiomyocytes are highly specialized, high-oxygen-requiring cells with large number of mitochondria. They occupy nearly 75% of the cardiac mass, but make only about one-third of the total cell number in the heart.…”

Identification and pharmacological characterization of succinate receptor agonists

“…In total, 32 male Wistar rats (250‐350 g, 3 months of age) originating from the University of Liège animal facility (Federal authorization for breeding animals LA1610002) were kept in a pathogen‐free (SPF) facility, at least two per ventilated cages in a controlled temperature and regular light/dark cycle. The non‐invasive tail–cuff method used to measure BP has been extensively described as an adequate method for the estimation of BP and routinely used in our lab (Bialy et al , ; Dogne et al , ).…”

Adenosine Receptors as a Biological Pathway for the Anti-Inflammatory and Beneficial Effects of Low Frequency Low Energy Pulsed Electromagnetic Fields

“…A beneficial effect of PEMF exposure on hypoxia-related conditions has been found through inhibition of hypoxia/reoxygenation-induced death of human renal proximal tubular cells via suppression of intracellular reactive oxygen species (ROS) production [ 33 ]. Moreover, it has been demonstrated that electromagnetic fields when applied prior to, during, and after the ischemic insult protect the heart against ischemia/reperfusion-induced cardiac contractile dysfunction and heart injury [ 34 ]. In acute experimental myocardial infarcts in rats, PEMFs were able to limit the area of necrosis caused by ischemic injury [ 35 ].…”