Scintigraphic imaging of programmed cell death, apoplcssis, in ischemic myocardium

为了确定这一过程在不同程度缺血中的时间过程、位置和程度，我们研究了不同冠状动脉闭塞间隔（20、15、10、5分钟）和再灌注时间（0.5、1.5、6、24小时、3天、14天）各组大鼠^<99m>Tc-annexin-V摄取。再灌注后^<99m>注射Tc-annexin-V， 1h后处死。双示踪放射自显影术评估^<99m>Tc-annexin-V摄取和危险面积。在所有5分钟闭塞和再灌注模型中，危险区域未观察到明显的^<99m> tc -膜联蛋白V摄取。在10min、15min和20min缺血再灌注模型中，根据缺血再灌注时间的严重程度，观察到显著的^<99m> tc -膜联蛋白V摄取。再灌注时间相同的各组大鼠，tc -膜联蛋白V摄取随缺血严重程度的变化而变化；越长遮挡时间摄取越高。缺血时间相同各组大鼠^<99m> tc -膜联蛋白V摄取在0.5 h再灌注模型中最高，且摄取随时间的延长而降低。在缺血20分钟时，观察到一定程度的梗死组织学证据。在缺血15、10、5 min时，缺血10、5 min组未见明显组织学变化。这些数据表明，膜联蛋白的结合取决于缺血的严重程度，从而导致广泛的组织学改变；即从梗塞到无明显组织学改变。tc -膜联蛋白V显像在无梗死的急性心肌缺血和梗死的评估中都是可行的。

To determine the time course, location and extent of this process in various severity of ischemia we studied ^<99m>Tc-annexin-V uptake in groups of rats following various intervals of coronary occlusion (20, 15, 10, 5 min) and reperfusion time (0.5, 1.5, 6, 24 hr, 3 day, 14 day). After reperfusion ^<99m>Tc-annexin-V was injected and 1 h later the rats were sacrificed. Dual tracer autoradiography was performed to assess ^<99m>Tc-annexin-V uptake and area at risk. In all 5-min occlusion and reperfusion models, no significant ^<99m>Tc-annexin V uptake was observed in the area at risk. In 10-min, 15-min, and 20-min ischemia and reperfusion models, significant ^<99m>Tc-annexin V uptake was observed depending on the severity of ischemia and reperfusion time. In each group of rats with the same reperfusion time, ^<99m>Tc-annexin V uptake depended on the severity of ischemia ; higher uptake in longer occlusion time. In each group of rats with the same ischemic time, ^<99m>Tc-annexin V uptake was highest in 0.5 h reperfusion model and the uptake decreased time dependently. In 20-min ischemia, a certain level of histological evidence of infarction was observed. In 15, 10, 5-min ischemia, there was no significant histological change was observed in 10-min and 5-min ischemia group. These data indicate that annexin binding depends on the severity of ischemia which results in the wide spectrum of histological change ; that is from infarction to no significant histological change. ^<99m>Tc-annexin V imaging may be feasible in the assessment of acute myocardial ischemia without infarction as well as infarction.