Mitochondrial dynamics as an underlying mechanism involved in aerobic exercise training-induced cardioprotection against ischemia-reperfusion injury

This study investigates the protective role of aerobic training against cardiac IR injury and the mitochondrial dynamics as a possible mechanism.Main methodsThirty-two male Wistar rats (8-week old) were divided into a control, sham, control + IR, and training + IR groups (8 rats each). Training group was exercised aerobically on a treadmill for 8 weeks (5 days/week). After 8 weeks, anesthetized rats underwent a left thoracotomy (sham, control + IR, and training + IR groups) to access the left anterior descending coronary artery, which was occluded by a silk suture for 30 min and released for 90 min of reperfusion (IR groups). Triphenyltetrazolium chloride staining was used to determine the infarct size. The gene expression of mitofusin 1 (Mfn1), mitofusin 2 (Mfn2), and dynamin-related protein 1 (Drp1) was evaluated by RT-PCR. A one-way ANOVA was used for statistical analysis with the significance level set at P ≤ 0.05.Key findingsCardiac infarct size was smaller In training + IR group (20.24 ± 5.7%) than in control + IR (35.9 ± 2.3%; P ≤ 0.05). Training + IR showed higher expression of Mfn1 and Mfn2 (P ≤ 0.05). Conversely, Drp1 expression was lower after training (P ≤ 0.05).SignificanceExercise-induced regulation of mitochondrial fusion and fission, leading to improvement of mitochondrial dynamics seems to be involved in the cardioprotection against IR injuries.
Source: Life Sciences - Category: Biology Source Type: research