Neutrophils recruited to the myocardium after acute experimental myocardial infarct generate hypochlorous acid that oxidizes cardiac myoglobin

• Myocardial inflammation after acute myocardial infarct (AMI) is linked to congestive heart failure.
• We characterized methionine sulfoxide products on cardiac Mb from left ventricular rat heart 24 h after coronary ligation.
• Mb-sulfoxide accumulation coincided with the recruitment and activation of neutrophils in the affected myocardium.
• Oxidation of the oxygen-carrying Mb in the damaged LV may affect heart function/recovery of viable myocardium after AMI.