TELETHONIN AS AN EARLY IMMUNOHISTOCHEMICAL MARKER IN LIGATION-INDUCED ISCHEMIC MYOCARDIAL INJURY

Abstract

In this study, acute myocardial injuries or necrosis were experimentally induced in calves and pigs by ligation of either the left anterior descending coronary artery or left circumflex branch for 30[Formula: see text]min without reperfusion. Various antibodies directed to structural and functional proteins of the sarcomere, as well as activated proteinases, were employed in immunohistochemistry to compare for their potentials to detect early myocardial injury. For comparison, the histological criteria (designated as “Method A”) of cardiomyocyte necrosis such as nuclear pyknosis, sarcoplasmic fragmentation, flocculation, and/or the presence of a contraction band, and inflammatory infiltration were also scored. Additional criteria (designated “Method B”) of changes in late reversible stage of cell injury such as irregular nuclear shape or hyperchromasia, sarcomplasmic hypereosinophilia with either swelling or atrophy in diameter, and perinuclear vacuolation likely of swollen organelles, were also scored. In this setting, telethonin (T-cap), cardiac troponin I (cTnI), the current gold standard, and Method B, were superior to others in detecting ligation-induced ischemic injury. Other markers were either less specific, or less sensitive, or inconclusive for the current application. In conclusion, telethonin may serve as an early immunohistochemical marker in ligation-induced ischemic myocardial injury due to a combination of biomechanical stress, hypoxia, and possibly additional factor as matrix metalloproteinase activation.