Physical Exercise and Regulation of Intracellular Calcium in Cardiomyocytes of Hypertensive Rats

Abstract

BackgroundRegulation of intracellular calcium (Ca2+) in cardiomyocytes is altered by hypertension; and aerobic exercise brings benefits to hypertensive individuals.Objective To verify the effects of aerobic exercise training on contractility and intracellular calcium (Ca2+) transients of cardiomyocytes and on the expression of microRNA 214 (miR-214) in the left ventricle of spontaneously hypertensive rats (SHR).MethodsSHR and normotensive Wistar rats of 16 weeks were divided into 4 groups -sedentary hypertensive (SH); trained hypertensive (TH); sedentary normotensive (SN); and trained normotensive (TN). Animals of the TH and TN groups were subjected to treadmill running program, 5 days/week, 1 hour/day at 60-70% of maximum running velocity for 8 weeks. We adopted a p ≤ 0.05 as significance level for all comparisons.ResultsExercise training reduced systolic arterial pressure in hypertensive rats. In normotensive rats, exercise training reduced the time to 50% cell relaxation and the time to peak contraction and increased the time to 50% decay of the intracellular Ca2+ transients. In SHR, exercise increased the amplitude and reduced the time to 50% decay of Ca2+ transients. Exercise training increased the expression of miR-214 in hypertensive rats only.ConclusionThe aerobic training applied in this study increased the availability of intracellular Ca2+ and accelerated the sequestration of these ions in left ventricular myocytes of hypertensive rats, despite increased expression of miR-214 and maintenance of cell contractility.

Digoxin Combined with Aerobic Interval Training Improved Cardiomyocyte Contractility

“…However, the effects of aerobic interval training and digoxin on Ca 2 + handling and this association with myocardial intracellular proteins have been poorly investigated. Although the literature reports that physical exercise favours Ca 2 + transport and increased Ca 2 + availability for cardiac contractility [4,56,57], our data did not reveal effects of association between digoxin and aerobic interval training on protein expression of SERCA2a, PLB and calcineurin. In the current study, the absence of changes in Ca 2 + handling in healthy hearts by digoxin alone and/or associated to aerobic interval training could be related to lack of need to raise the intracellular Ca 2 + since the animals did not have any pathological condition as heart failure.…”

Crossfit Practice: An Electromyographic Analysis of Masticatory Muscles

“…When evaluating the dynamic movements of the stomatognathic system, especially the usual clinical condition of chewing, it is known that to affect and regulate the contractility of the skeletal muscle, thin lament proteins respond to calcium (Ca 2 + ) [29,30] and high-intensity aerobic training. In addition, there is an increase in the availability of the divalent cation ion inside the cells [31], promoting a stimulus for the release of neurotransmitters, contracting the muscles with proliferation of potential of action [32] that assists in the dynamic functional performance of the human body.…”

Exercise Mediates Heart Protection via Non-coding RNAs

“…Interestingly, another study showed that in hypertensive rats, ET reduced systolic arterial pressure and increased the accessibility of intracellular Ca 2+ in myocytes of the left ventricle as well as the expression of miR-214 (Rodrigues et al, 2018). However, the results contradicted the author's expectations and data from previous research that revealed decreased miR-214 expression and increased expression of sarcoplasmic reticulum Ca 2+ -ATPase (SERCA2a), the main facilitator of Ca 2+ translocation from the cytosol to the sarcoplasmic reticulum (Melo et al, 2015).…”