Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
Faculty of Health Science, Hyogo University, Kakogawa, Japan.
Ann Nucl Med. 2021 Jan;35(1):59-64. doi: 10.1007/s12149-020-01535-x. Epub 2020 Oct 8.
I-15-(p-iodophenyl)-3(R,S)-methylpentadecanoic acid ([I]BMIPP), a fatty acid analog, is widely used for the diagnosis of cardiac diseases. Feeding condition is one of the important factors in the myocardial fatty acid uptake, which may also affect myocardial accumulation of [I]BMIPP and image quality of [I]BMIPP scintigraphy. However, the relationship between the myocardial accumulation of [I]BMIPP and the feeding condition is not entirely clear. Therefore, we determined the myocardial accumulation of [I]BMIPP in mice at various metabolic statuses induced by fasting in comparison with the hepatic accumulation.
Fed or fasted (6-, 12-, and 24-h fasted) mice were intravenously injected with [I]BMIPP (35.2-75.0 kBq, 4 nmol). Radioactivities in the heart and liver were measured at 1, 5, 10, 30, 60, and 120 min after the injection (n = 5-15/time point for each group), and then, the heart-to-liver (H/L) ratios were calculated.
The myocardial accumulation level of [I]BMIPP in the fed group was almost the same as that in the 6-h-fasted group at each time point, although it was decreased by 12- and 24-h fasting. The H/L ratios of [I]BMIPP accumulation level were significantly decreased by fasting (1.92 ± 0.22, 1.45 ± 0.13, 1.12 ± 0.13, and 0.91 ± 0.15 at 10 min, and 3.30 ± 0.62, 2.09 ± 0.35, 1.79 ± 0.34, and 1.27 ± 0.06 at 30 min after the injection, respectively, for the fed group and the 6-, 12-, and 24-h-fasted groups; p < 0.0001), largely owing to the increase in the hepatic accumulation level in the fasting groups.
Although short-period (6 h) fasting did not affect the myocardial accumulation level of [I]BMIPP, the hepatic accumulation level was increased. The present results indicate that the fed condition may provide higher-contrast images in myocardial [I]BMIPP scintigraphy.
I-15-（对碘苯基）-3（R，S）-甲基十五烷酸（[I]BMIPP）是一种脂肪酸类似物，广泛用于心脏病的诊断。进食状态是心肌摄取脂肪酸的重要因素之一，它也可能影响[I]BMIPP 的心肌蓄积和[I]BMIPP 闪烁显像的图像质量。然而，[I]BMIPP 的心肌蓄积与进食状态之间的关系尚不完全清楚。因此，我们比较了禁食诱导的各种代谢状态下（禁食 6、12 和 24 小时）小鼠的[I]BMIPP 心肌蓄积与肝脏蓄积。
静脉注射[I]BMIPP（35.2-75.0 kBq，4 nmol）给进食或禁食（6、12 和 24 小时禁食）的小鼠。在注射后 1、5、10、30、60 和 120 分钟测量心脏和肝脏的放射性活度（每组 5-15 个时间点），然后计算心脏与肝脏的（H/L）比值。
尽管 12 和 24 小时禁食后，[I]BMIPP 的心肌蓄积水平有所下降，但在各个时间点，进食组的心肌蓄积水平与 6 小时禁食组几乎相同。[I]BMIPP 蓄积水平的 H/L 比值随着禁食而显著降低（10 分钟时分别为 1.92 ± 0.22、1.45 ± 0.13、1.12 ± 0.13 和 0.91 ± 0.15，30 分钟时分别为 3.30 ± 0.62、2.09 ± 0.35、1.79 ± 0.34 和 1.27 ± 0.06，进食组和 6、12 和 24 小时禁食组；p<0.0001），这主要是由于禁食组肝脏蓄积水平增加所致。
尽管短期（6 小时）禁食不会影响[I]BMIPP 的心肌蓄积水平，但肝脏蓄积水平会增加。本研究结果表明，进食状态可能在心肌[I]BMIPP 闪烁显像中提供更高对比度的图像。
