Níveis distintos de Hsp72 no miocárdio de ratas em resposta aos exercícios voluntário e for？ado

background: physical exercise induces hemodynamic stress. objective: to evaluate if voluntary running and forced running induced different levels of stress protein (hsp72) in the myocardium of female wistar rats. methods: female rats were randomly assigned to the following groups: forced treadmill running group (fr; n= 6), voluntary running group (vr; n=6) and control group (c; n=6). vr group animals had free access to running wheels, and those from fr group underwent a running program on a treadmill (18 m/min, 60 min/day, 5 days/wk) for 8 weeks. left ventricle (lv) and right ventricle (rv) fragments were collected at sacrifice, and the relative immunoblot contents of stress protein (hsp72) were determined. results: vr animals ran on average 4.87 km/wk, and fr rats ran 4.88 km/wk. animals from vr and fr groups had less body weight gain (p<0.05) than those from c group (81.67 ± 11.95g vs 81.17 ± 10.18g vs 111.50 ± 2.26g, respectively). heart weight/body weight ratio was not significantly different (p>0.05) among vr, fr and c groups (4.54 ± 0.79 mg/g vs 4.94 ± 0.89 mg/g vs 4.34 ± 0.87 mg/g, respectively). fr group animals had levels of hsp72 (p<0.05) higher than those from vr, both in lv (287.45 ± 35.86 % vs 135.59 ± 5.10 %, respectively) and rv (241.31 ± 25.83 % vs 137.91 ± 45.20 %, respectively). conclusion: voluntary running and forced running induced different levels of hsp72 in the myocardium of female wistar rats.