Rodrigues Joel Alves, Prímola-Gomes Thales Nicolau, Soares Leôncio Lopes, Leal Tiago Ferreira, Nóbrega Clara, Pedrosa Danillo Laviola, Rezende Leonardo Mateus Teixeira, Oliveira Edilamar Menezes de, Natali Antonio Jose
Universidade Federal de Viçosa (UFV), Viçosa, MG - Brazil.
Universidade de São Paulo (USP), São Paulo, SP - Brazil.
Arq Bras Cardiol. 2018 Aug;111(2):172-179. doi: 10.5935/abc.20180113. Epub 2018 Jul 2.
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.
高血压会改变心肌细胞内钙离子（Ca2+）的调节；有氧运动对高血压患者有益。
验证有氧运动训练对自发性高血压大鼠（SHR）心肌细胞收缩性、细胞内钙离子（Ca2+）瞬变以及左心室中微小RNA 214（miR-214）表达的影响。
将16周龄的SHR和血压正常的Wistar大鼠分为4组——久坐不动的高血压组（SH）；训练后的高血压组（TH）；久坐不动的血压正常组（SN）；训练后的血压正常组（TN）。TH组和TN组的动物接受跑步机跑步计划，每周5天，每天1小时，速度为最大跑步速度的60-70%，持续8周。所有比较的显著性水平均采用p≤0.05。
运动训练降低了高血压大鼠的收缩压。在血压正常的大鼠中，运动训练缩短了细胞50%舒张时间和收缩峰值时间，并延长了细胞内Ca2+瞬变50%衰减时间。在SHR中，运动增加了Ca2+瞬变的幅度并缩短了其50%衰减时间。运动训练仅增加了高血压大鼠中miR-214的表达。
本研究中应用的有氧运动训练增加了高血压大鼠左心室心肌细胞内Ca2+的可用性，并加速了这些离子的隔离，尽管miR-214表达增加且细胞收缩性得以维持。
