The results about the myocardial protection effects of the nitric oxide precursor L-arginine upon reperfusion injury after ischemia are diverse. These diversities may be model dependent. Experiments were designed and performed to investigate
myocardial
protection effects according to the concentration of L-arginine. The isolated rat hearts were subjected in a 30 minutes of normothermic ischemia and reperfused for 30 minutes with reperfusate containing 0,1,2,3,4 mM/L L-arginine. After 30 minutes
of
reperfusion, group with l and 2mM/L L-arginine showed a trend of better recovery in left ventricular systolic function(left ventricular developed pressure, positive maximum dp/dt), diastolic function(negative maximum dp/dt) and coronary flow
compared to
control group(reperfusate with no L-arginine). Recovery was impaired with a lrigher concentration, and at 4mM/L L-arginine recovery was worse than contro(p<0.05). These results suggest that optimal concentration of L-arginine is important for the
recovery of myocardial and endothelial function after ischemia and reperfusion.
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