Short-term exercise training improves cardiac function associated to a better antioxidant response and lower type 3 iodothyronine deiodinase activity after myocardial infarction

Abstract

AimsWe assessed the effects of a short-term exercise training on cardiac function, oxidative stress markers, and type 3 iodothyronine deiodinase (D3) activity in cardiac tissue of spontaneously hypertensive rats (SHR) following experimental myocardial infarction (MI).MethodsTwenty-four SHR (aged 3 months) were allocated to 4 groups: sham+sedentary, sham+trained, MI+sedentary and MI+trained. MI was performed by permanent ligation of the coronary artery. Exercise training (treadmill) started 96 hours after MI and lasted for 4 weeks (~60% maximum effort, 4x/week and 40 min/day). Cardiac function (echocardiography), thioredoxin reductase (TRx), total carbonyl levels, among other oxidative stress markers and D3 activity were measured. A Generalized Estimating Equation was used, followed by Bonferroni’s test (p<0.05).ResultsMI resulted in an increase in left ventricular mass (p = 0.002) with decreased cardiac output (~22.0%, p = 0.047) and decreased ejection fraction (~41%, p = 0.008) as well as an increase in the carbonyl levels (p = 0.001) and D3 activity (~33%, p<0.001). Exercise training resulted in a decrease in left ventricular mass, restored cardiac output (~34%, p = 0.048) and ejection fraction (~20%, p = 0.040), increased TRx (~85%, p = 0.007) and reduced carbonyl levels (p<0.001) and D3 activity (p<0.001).ConclusionsOur short-term exercise training helped reverse the effects of MI on cardiac function. These benefits seem to derive from a more efficient antioxidant response and lower D3 activity in cardiac tissue.

Individuals with controlled hypertension show endothelial integrity following a bout of moderate-intensity exercise: randomized clinical trial

“…All analyses of oxidative stress were consistent with previous studies of our group 60 , 61 . In short, sulfhydryl content was determined as described by Aksenov and Markesbery 62 , where 5-thio-2-nitrobenzoic acid (TNB) derived from the reaction of thiols with 5,5′-dithiobis (2-nitrobenzoic acid) forms a yellow-colored derivative that is read in a spectrophotometer by measuring the absorbance at 412 nm.…”

Preventive aerobic training preserves sympathovagal function and improves DNA repair capacity of peripheral blood mononuclear cells in rats with cardiomyopathy

“…Prior to the exericse training protocol and at the end, maximum effort capacity was measured by the exercise test 85 . After an adaptation period (3 days) on the treadmill at a speed of 0.3 km/h (15 min), the maximal exercise test was then performed individually at an initial speed of 0.3 km/h with increments of 0.3 km/h every 3 min until voluntary exhaustion of the animal.…”

“…Exercise training consisted of a four-weeks moderate-intensity aerobic treadmill training program four times a week 85 , at 0% grade, before DOX or saline administration. The adopted mean intensity was 50% to 80% of the maximum speed evaluated according to ET, with a progressive increment of time.…”

Deiodinases and the Three Types of Thyroid Hormone Deiodination Reactions

“…Interestingly, correction of the redox state (decreased carbonyl levels) and a reduction in DIO3 activity in only 4 weeks of exercise training was previously observed in an experimental model of MI, resulting in improvements in cardiac function in terms of left ventricular mass, cardiac output, and the ejection fraction (assessed by echocardiography). A negative correlation of DIO3 with the maximum effort capacity (evaluated by an exercise stress test) was also found [ 81 ]. Thus, it is possible to consider exercise as a non-pharmacological tool to help to restore antioxidant defenses and T3 biological activity [ 82 , 83 ].…”