Artigo
Physical exercise and regulation of intracellular calcium in cardiomyocytes of hypertensive rats
Author
Rodrigues, Joel Alves
Prímola-Gomes, Thales Nicolau
Leal, Tiago Ferreira
Pedrosa, Danillo Laviola
Rezende, Leonardo Mateus Teixeira
Natali, Antonio Jose
Nóbrega, Clara
Oliveira, Edilamar Menezes de
Institutions
Abstract
Link errado. Favor verificar. Regulation of intracellular calcium (Ca2+) in cardiomyocytes is altered by hypertension; and aerobic exercise brings benefits to hypertensive individuals. 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). SHR 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. Exercise 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. The 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.