Does exercise training lessen ischemia-induced dysfunction of resistance vessels in stunned myocardium?

We hypothesized that exercise training attenuates ischemia-induced endothelial dysfunction of coronary resistance vessels in acutely-stunned (Stun) myocardium. Rats were treadmill-trained (Ex+Stun, n=7) or cage-confined (Stun, n=11) for 10 weeks. Arterial and left ventricular pressure, and systolic wall thickening (Wth), then were measured in response to 3 cycles of ischemia (I; coronary occlusion, 10 min) and reperfusion (R; 10 min) to induce stunning. Age-matched rats served as sham-operated controls (Sham, n=12). After the third I/R (or sham) cycle, resistance vessels from the stunned myocardium were dissected and mounted in a myograph to evaluate endothelium-dependent (ACh) and independent (SNP) function, *p<0.05 vs Stun and Ex+Stun. Our results suggest that exercise training does not attenuate ischemia-induced endothelial dysfunction in this model of myocardial stunning. (Graph Presented).