Exercise Training Preserves Coronary Flow and Reduces Infarct Size after Ischemia-Reperfusion in Rat Heart

Cardiopulmonary Physical Therapy Journal, Mar 2004

Exercise Training Preserves Coronary Flow and Reduces Infarct Size after Ischemia-Reperfusion in Rat Heart. Brown DA, Jew KN, Sparagna GC, Musch Tl, Moore RL. Reprinted with permission from J Appl Physiol. 2003;95: 2510-2518. © 2003 American Physiologic Society.

The effect of endurance training on the resistance of the heart to left ventricular (LV) functional deficit and infarction after a transient regional ischemia and subsequent reperfusion was examined. Female Sprague-Dawley rats were randomly assigned to an endurance exercise training (Tr) group or a sedentary (Sed) control group. After 20 wk of training, hearts were excised, perfused, and instrumented for assessment of LV mechanical function, and the left anterior descending coronary artery was occluded to induce a transient regional ischemia (1 h) that was followed by 2 h of reperfusion. Throughout much of the regional ischemiareperfusion protocol, coronary flow rates, diastolic function, and LV developed pressure were better preserved in hearts from Tr animals. During the regional ischemia, coronary flow to myocardium outside the ischémie zone at risk (ZAR) was maintained in Tr hearts, whereas it progressively fell in Sed hearts. On release of the coronary artery ligature, flow to the ZAR was greater in Tr than in Sed hearts, lnfarct size, expressed as a percentage of the ischémie ZAR, was significantly smaller in hearts from Tr rats (24 ± 3 vs. 32 ± 2% of ZAR, P