Formation of protein carbonyls during myocardial reperfusion by coronary angioplasty

The quantitation of myocardial reperfusion injury in patients often creates problems due to lack of specific markers. Although malondialdehyde provides an index of oxidative damage, we have little information regarding effects on membrane structure and function. Therefore we investigated the effect of ischemia/reperfusion on the kinetics of protein modification along with lipid peroxidation during coronary angioplasty. Venous blood,samples were collected before angioplasty and at various intervals after primary stage of balloon deflation from humans to quantitate the above parameters. A significant transient rise in the concentration of protein carbonyls in serum (p < 0.001) was observed soon after successful reperfusion which parallels with that of lipid peroxides. This increase of protein carbonyls is an actual reflection of the increased rate of amino acid modification in membrane proteins. These structural modifications can alter lipid-protein interactions resulting in disturbed membrane functions. This study suggests that protein modification and lipid peroxidation play significant role in the pathogenesis of myocardial reperfusion injury. Further this assessment of structural modification in proteins provides an important reliable technique to detect and quantitate the exact nature and extent of myocardial injury.