The myocardial uptake of 15-(p-iodophenyl)-6- tellurapentadecanoic
acid (
TPDA ) was studied in dogs during
coronary occlusion and after reperfusion. In eight dogs with a 3 hour occlusion (Group A) with (n = 5) and without (n = 3) 30 minutes of reperfusion,
iodine-125 TPDA uptake correlated well with
microsphere myocardial blood flow over a wide range of flow levels (n = 111, r = 0.94). In six dogs with a 20 minute occlusion of the left anterior descending coronary artery and 1 hour of reperfusion (Group B),
iodine-125 TPDA uptake correlated equally well with myocardial blood flow (n = 37, r = 0.90). There was no difference between the slopes of regression lines for Groups A and B, indicating no release from the myocardium of radioiodinated
TPDA . Dual radiolabeling of
TPDA was employed in five Group A animals by
intravenous injection of
iodine-125 TPDA during
coronary occlusion and
iodine-131 TPDA after reperfusion. In 63 myocardial samples,
microsphere reperfusion flow and
iodine-131 TPDA uptake were closely correlated (r = 0.91). As with
monovalent cations, at myocardial flows higher than control flows,
iodine-131 TPDA uptake was flow-limited. It is concluded that: 1) radioiodinated
TPDA accurately reveals severely ischemic areas of myocardium without myocardial release of the
radionuclide in
coronary occlusions lasting 20 to 180 minutes and followed by reperfusion, and 2) double radiolabeled
TPDA allows assessment of both occlusion and reperfusion flows. This compound may find an application in the measurement of
infarct size and the evaluation of interventional
therapies in acute
myocardial infarction.