Effects of exercise training on cardiac function, gene expression, and apoptosis in rats

Abstract

This study determined the effects of exercise training on cardiac function, gene expression, and apoptosis. Rats exposed to a regimen of treadmill exercise for 13 wk had a significant increase in cardiac index and stroke volume index and a concomitant decrease in systemic vascular resistance compared with both age-matched and body weight-matched sedentary controls in the conscious state at rest. In exercise-trained animals, there was no change in the expression of several marker genes known to be associated with pathological cardiac adaptation, including atrial natriuretic factor, beta-myosin heavy chain, alpha-skeletal and smooth muscle actins, and collagens I and III. Exercise training, however, produced a significant induction of alpha-myosin heavy chain, which was not observed in rats with myocardial infarction. No histological features of cardiac apoptosis were observed in the treadmill-trained rats. In contrast, apoptotic myocytes were detected in animals with myocardial infarction. In summary, exercise training improves cardiac function without evidence of cardiac apoptosis and produces a pattern of cardiac gene expression distinct from pathological cardiac adaptation.

Response of caspase-independent apoptotic factors to high salt diet-induced heart failure

“…In brief, at 6 weeks of age, rats in the exercise group exercised daily on a rodent treadmill (Columbus Instruments, Columbus, OH) following a modified training program which comprised a 3-wk progressive intensity-increasing period followed by a 3-wk maintenance period [13,14]. Animals exercised at the running speed of 20 m/min at a 5° incline for 90 min per session in the maintenance period.…”

The Effects of Aging and Physical Activity on Doppler Measures of Diastolic Function

“…25,26 Furthermore, exercise appears to have an antiapoptotic effect on myocytes that likely enhances chamber distensibility because myocytes are less stiff than collagen. 26,27 Thus, it is possible that lifelong endurance training may maintain myocyte volume and cell size and limit the development of fibrosis, thus preserving cardiac compliance.In contrast, myocardial relaxation is predominantly influenced by myocyte calcium handling, but appears to be species specific. For example, endurance training enhances calcium uptake and improves myocyte excitation-contraction coupling in rats, but not in canines.…”

Androgen deprivation therapy and cardiac function: effects of endurance training

“…Thirteen weeks of endurance training has been shown to improve cardiac function and promote a significant increase in a-MHC mRNA (with no increase in b-MHC mRNA) in healthy male rats. 9 This suggests that endurance training promotes an upregulation in a-MHC mRNA which in the present study may have counteracted the Zoladexinduced upregulation in b-MHC.…”

“…Exercise training has been shown to improve cardiac function in both healthy 9 and diseased 10 models and has been shown to attenuate chemotherapy induced cardiovascular dysfunction. 11,12 The positive adaptations associated with endurance exercise training are associated with improved ventricular contractile force which potentially could attenuate the cardiac dysfunction associated with ADT.…”