Reinhardt C P, Weinstein H, Marcel R, Leppo J A
Department of Nuclear Medicine, University of Massachusetts Medical Center, Worcester 01655-0243, USA.
J Nucl Med. 1995 Sep;36(9):1645-53.
Radiolabeled fatty acids such as 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) have unique metabolic properties of potential use as myocardial perfusion tracers. Accordingly, we compared the in vivo pattern of uptake of BMIPP and 201Tl in hypoperfused rabbit myocardium.
Animals were intubated, ventilated and their arterial pressures monitored. A left thoracotomy was performed. After ligation of a major branch of the circumflex artery, an intravenous injection of BMIPP or BMIPP/201TI was given. Radiolabeled microspheres were used to document the area of risk. After the circulation period, the animals were killed. Tracer deposition within the hearts was determined by either dual-tracer autoradiography (Protocol I) or by segmental tissue analysis (Protocol II).
Dual-tracer autoradiographic activity profiles for BMIPP were comparable to those of 201TI. Moreover, the two tracers yielded similar values for normal-to-defect contrast and defect size. The myocardial activity concentration of BMIPP for both protocols correlated strongly with coronary blood flow and compared favorably with 201TI.
BMIPP and 201TI accurately delineate areas of hypoperfusion distal to a coronary occlusion. Therefore, differences in the myocardial distribution of BMIPP and 201TI in clinical studies may be related to cellular fatty acid metabolism.
放射性标记的脂肪酸，如15-（对碘苯基）-3-R，S-甲基十五烷酸（BMIPP），具有独特的代谢特性，有可能用作心肌灌注示踪剂。因此，我们比较了BMIPP和201Tl在灌注不足的兔心肌中的体内摄取模式。
动物进行插管、通气并监测动脉压。进行左胸切开术。在结扎回旋支动脉的一个主要分支后，静脉注射BMIPP或BMIPP/201Tl。使用放射性标记的微球记录危险区域。循环期结束后，处死动物。通过双示踪剂放射自显影（方案I）或节段性组织分析（方案II）确定心脏内示踪剂的沉积。
BMIPP的双示踪剂放射自显影活性曲线与201Tl的相似。此外，两种示踪剂在正常与缺损对比度和缺损大小方面产生相似的值。两种方案中BMIPP的心肌活性浓度与冠状动脉血流密切相关，与201Tl相比效果良好。
BMIPP和201Tl能准确描绘冠状动脉闭塞远端的灌注不足区域。因此，临床研究中BMIPP和201Tl在心肌分布上的差异可能与细胞脂肪酸代谢有关。
