Noriyasu Kazuyuki, Mabuchi Megumi, Kuge Yuji, Morita Koichi, Tsukamoto Takahiro, Kohya Tetsuro, Kitabatake Akira, Tamaki Nagara
Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Eur J Nucl Med Mol Imaging. 2003 Dec;30(12):1644-50. doi: 10.1007/s00259-003-1305-z. Epub 2003 Sep 3.
Several clinical studies have shown that iodine-123 labelled 15-(p-iodophenyl)-3-(R, S)-methylpentadecanoic acid (BMIPP) uptake is often lower than the uptake of perfusion tracers in patients with ischaemic heart disease. However, BMIPP accumulation may not decrease during the acute phase of a stunned myocardium in patients with acute coronary syndrome. We evaluated serial changes in BMIPP and perfusion tracer uptake in the myocardium after ischaemia. We performed a 20-min left coronary artery occlusion followed by reperfusion in male Wistar rats. One hour after the reperfusion, echocardiography was performed. Intravenous injection of iodine-125 labelled BMIPP and thallium-201 was performed 1 day (acute group) and 5 days (subacute group) after the operation. To determine the myocardial distribution of 125I-BMIPP and 201Tl, dual-tracer autoradiography was conducted. We identified regions of interest in the anterolateral wall as an area at risk and in the inferoseptum as a remote control area. The anterolateral wall/inferoseptum ratio (A/I ratio) was calculated to compare the distributions of 125I-BMIPP and 201Tl. Coronary occlusion induced hypokinesia in the anterolateral region 1 h after the reperfusion. The A/I ratio of 125I-BMIPP was significantly higher than that of 201Tl in the acute group (1.01 +/- 0.15 vs 0.80 +/- 0.23, P<0.001). On the other hand, there was no significant difference between the A/I ratios of 125I-BMIPP and 201Tl in the subacute group (0.88 +/- 0.18 vs 0.85 +/- 0.18). Two rats showed a significantly lower A/I ratio of 125I-BMIPP than 201Tl in the subacute phase. These data suggest that BMIPP uptake is preserved despite a decrease in perfusion in the acute phase after ischaemia. In the subacute phase, on the other hand, BMIPP uptake is similar to or even lower than thallium uptake. Since BMIPP uptake may change with time after ischaemia, careful interpretation of BMIPP uptake after ischaemia is required in a clinical setting.
多项临床研究表明，在缺血性心脏病患者中，碘-123标记的15-（对碘苯基）-3-（R，S）-甲基十五烷酸（BMIPP）摄取量通常低于灌注示踪剂的摄取量。然而，在急性冠状动脉综合征患者的心肌顿抑急性期，BMIPP的蓄积可能不会减少。我们评估了缺血后心肌中BMIPP和灌注示踪剂摄取的系列变化。我们对雄性Wistar大鼠进行了20分钟的左冠状动脉闭塞，随后进行再灌注。再灌注1小时后，进行超声心动图检查。术后1天（急性组）和5天（亚急性组）静脉注射碘-125标记的BMIPP和铊-201。为了确定125I-BMIPP和201Tl的心肌分布，进行了双示踪剂放射自显影。我们将前壁区域确定为危险区域，将下间隔区域确定为对照区域。计算前壁/下间隔比值（A/I比值）以比较125I-BMIPP和201Tl的分布。冠状动脉闭塞在再灌注1小时后导致前壁区域运动减弱。急性组中125I-BMIPP的A/I比值显著高于201Tl（1.01±0.15对0.80±0.23，P<0.001）。另一方面，亚急性组中125I-BMIPP和201Tl的A/I比值之间无显著差异（0.88±0.18对0.85±0.18）。两只大鼠在亚急性期显示125I-BMIPP的A/I比值显著低于201Tl。这些数据表明，尽管缺血后急性期灌注减少，但BMIPP摄取得以保留。另一方面，在亚急性期，BMIPP摄取与铊摄取相似甚至更低。由于缺血后BMIPP摄取可能随时间变化，因此在临床环境中需要仔细解读缺血后的BMIPP摄取情况。
