CARDIAC TROPONIN-I AND TROPONIN-T ALTERATIONS IN DOG HEARTS WITH MYOCARDIAL-INFARCTION - CORRELATION WITH INFARCT SIZE

We studied the distribution of cardiac troponins I (cTnI) and T (cTnT) in ischemic left ventricular (LV) tissue in 7 infarct zones, 7 remote nonischemic LV areas, and 7 nonischemic areas each from the right ven tricle and circumflex in art acute coronary artery occlusion dog model to correlate myocardial loss of troponins with infarct size 3 weeks a fter the infarction and to determine whether the decrease of troponins in ischemic myocardium can be used to assess the infarct size in dogs after coronary occlusion. The serum profiles for time vs mean cTnI an d cTnT concentrations in 6 dogs after occlusion showed peak concentrat ions at 1 day and 5 days, respectively. The concentrations of troponin s were similar in all nonischemic zones. However; cTnI and cTnT decrea sed significantly in the LV ischemic tissues. Loss of cTnT, but not cT nI, in ischemic LV tissues correlated significantly with infarct size 3 weeks after the infarction. Biochemical alterations suggest that the increases in serum troponins after the infarction parallel the decrea ses in tissue concentrations of troponins.