Abstract
BACKGROUND: Stroke is commonly accompanied by motor disorders secondary to the initial injury, and at the mitochondrial level, there is an increase in oxidative stress, causing tissue damage and relating to alteration in motor function. Functional electrical stimulation (FES) therapies can be useful in stroke patients aimed at restoring motor function and improving life quality. Several studies have recently proposed that electrical stimulation modulates mitochondrial biogenesis and physiology; however, the effect of FES on individual complexes comprising the mitochondrial electron transport chain (mETC) remains unknown. METHODS: To study the effect of FES therapy on the activity of the mETC, in vitro analyses were conducted using UV-spectrophotometry of the activity of the complexes (I, II, and IV), glycerol-3-phosphate dehydrogenase (G3PDH), and monoamine oxidase (MAO) in peripheral blood mononuclear cells (PBMCs) obtained from stroke patients. Patients' activity of complex II and MAO was also determined in platelets. Analyses were measured before and after 12 rehabilitation sessions based on FES therapy combined with physical exercises. RESULTS: The results showed that the activity of the mETC, G3PDH, and MAO was significantly reduced in pre-intervention stroke patients compared to healthy volunteers, both in PBMCs and platelets, except for complex II in platelets and MAO in PBMCs. Interestingly, FES intervention increased the mETC, G3PDH, and MAO activity in both cell types of stroke patients. CONCLUSIONS: This preliminary study indicates that intervention can restore motor function and mitochondrial activity, which are damaged in stroke patients. However, more research is needed to determine if changes in mitochondrial activity can be used as biomarkers of the pathology and/or the efficacy of intervention.