This study evaluated the effects of a linear block strength training programme on the parameters of cardiac remodelling in spontaneously hypertensive rats. Thirty-nine rats were equally distributed in four groups: normotensive sedentary, normotensive trained, hypertensive sedentary and hypertensive trained. The strength training protocol was organized in three mesocycles of 4 weeks, with an increase in the training load organized in a linear fashion for each block, considering the weight established in the maximum loaded load test. The following parameters were evaluated: ventricular function assessed by echocardiogram, caudal blood pressure, ventricular haemodynamics and cardiac masses. Two-way analysis of variance was used to determine the differences between the group and time.
After 12 weeks of training, the hypertensive trained group presented the following results: increased muscle strength, reduced blood pressure, reduced heart rate, isovolumetric relaxation time and total collagen content, with increased cardiac function, without promoting changes in the mass and nuclear volume of cardiomyocytes. Also, blood pressure reduction seems to be associated with both muscle strength adjustments and total load progress.
The findings of this study showed that the training programme carried out attenuated systemic arterial pressure and preserved the ventricular function of spontaneously hypertensive rats without cardiac mass change.
aDepartment of Nephrology, Federal University of São Paulo
bDepartment of Physical Education, Laboratory of Morphoquantitative Studies and Immunohistochemistry, São Judas Tadeu University
cDepartment of Cardiology, Federal University of São Paulo, São Paulo-SP
dDepartment of Physical Education, Federal University of São Paulo, Campus Baixada Santista, Santos-SP
eLaboratory of Experimental Physiology and Biochemistry of the Center of Physical Education and Sports, Federal University of Espirito Santo, Vitoria-ES, Brazil
Correspondence to Danilo S. Bocalini, PhD, Experimental Physiology and Biochemistry Laboratory, Physical Education and Sports Center of the Federal University of Espirito Santo, Rua Ludwik Macal, 403, apto 101, Jardim da Penha, Vitoria, Espirito Santo 29060-030, Brazil. E-mail: email@example.com
Abbreviations: +dP/dt, maxima positive time derivatives of the developed pressure; –dP/dt, maxima negative time derivatives of the developed pressure; FS, fractional shortening; LV, left ventricle; LVAWT, left ventricle anterior wall thickness; LVEDD, left ventricle end-diastolic diameter; LVEDP, Left ventricle end-diastolic pressure; LVESD, left ventricle end-systolic diameter; LVPWT, left ventricle posterior wall thickness; LVSP, left ventricle systolic pressure; RWT, relative wall thickness
Received 23 January, 2019
Revised 8 June, 2019
Accepted 10 June, 2019