Articles : Effects of Exercise Training on Myocadial Expression of Angiotensin Converting Enzyme and Apoptotic Protein in Spontaneously Hypertensive Rats

Journal of Exercise Nutrition & Biochemistry 2004;8(2):243-250.

Abstract

This study determined the effects of exercise training on cardiac function and the expression of angiotensin-converting enzyme (ACE) and apoptotic proteins. Spontaneously hypertensive rats (SHR) exposed to a regimen of treadmill exercise for 12 weeks had a significantly reduced body weight, heart rate, blood pressures and cardiac wall thickness compared with non-exercise SHR. Therefore, treadmill exercise was sufficient to induce clearly physiological adaptation in the SHR. In the exercise-trained SHR, there was significant reduction in the expression of angiotensin-converting enzyme (ACE) known to be associated with hypertension and pathological cardiac hypertrophy. Furthermore, there was significant reduction in DNA fragments and several marker proteins, including bax and caspase-3 (32 kDa, 20 kDa) known to be associated with apoptosis. Therefore, cardiac apoptosis was detected in non-exercise SHR. Thus, treatment of hypertension with exercise was associated with a reduction in apoptosis suggesting that exercise interfered with a signal transduction pathway of apoptosis and prevented pathological hypertrophy in the left ventricle by altering angiotensin-converting enzyme (ACE). In conclusion, there was a hypertensive induced-increase in apoptosis in the non-exercise SHR and that endurance exercise training interfered a signal transduction pathway of apoptosis secondary to the pathological cardiac hypertrophy.

Key Words: Spontaneously hypertensive rat, treadmill exercise, apoptosis, pathological hypertrophy