Comparative studies of Cu-64-ATSM and C-11-acetate in an acute myocardial infarction model:: Ex vivo imaging of hypoxia in rats

Copper labeled diacetyl-bis(N-4-methylthiosemicarbazone) (Cu-ATSM) is a promising agent for the imaging of hypoxic tissues. In the present study Cu-64 (t(1/2) - 12.8 h) labeled Cu-ATSM was used in combination with C-11 (t(1/2) = 20.3 min) labeled acetate as a regional perfusion marker to visualize hypoxic rat heart tissue in an acute left anterior descending (LAD) coronary artery occluded rat model using an ex vivo tissue slice imaging technique. Cu-64-ATSM was injected intravenously c.a. 10 min after occlusion and rats were sacrificed by cervical dislocation 10 min after injection. Carbon-11-acetate was injected 1 min before sacrifice to obtain a measure of blood flow. The heart-was dissected, frozen, and cut into l-mm thick slices with a gauged slicer, and C-11 images were obtained with an electronic autoradiography instrument. After decay of C-11, Cu-64 images were obtained in the same manner. In ischemic regions, where there was low C-11 accumulation, Cu-64 showed high accumulation when compared with normal regions. In rats with a large occlusion, the center of the ischemia did not show any accumulation of either C-11 or Cu-64, indicating no blood supply. Cu-ATSM appears to be useful for the detection of hypoxia with contrast being observed at short times (10 min) postinjection. NUCL MED BIOL 26;1:117-121 1999. (C) 1998 Elsevier Science Inc.