Yamamoto F, Shibata S, Watanabe S, Masuda K, Maeda M
Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
Nucl Med Biol. 1996 May;23(4):479-86. doi: 10.1016/0969-8051(96)00025-x.
The in vivo uptake and distribution of 6-deoxy-6-[18F]fluoro-L-ascorbic acid (18F-DFA) were investigated in rat brains following postischemic reperfusion. Global cerebral ischemia was induced in male Wistar rats for 20 min by occlusion of four major arteries. Two time points were chosen for 18F-DFA injection to rats subjected to cerebral ischemia, at the start of recirculation and 5 days following recirculation. The rats were then killed at 2 h after tail-vein administration of 18F-DFA and tissue radioactivity concentration was determined. Increased uptake of radioactivity in particular brain regions, including the cerebral cortex, hypothalamus, and amygdala following injection of 18F-DFA, compared to the sham-operated control, was observed 5 days after reperfusion. Similar results were also obtained in in vitro experiments using brain slices. Abnormal in vivo accumulation of 45Ca, a marker of regional postischemic injury, was observed in these brain regions in tissue dissection experiments. Furthermore, metabolite analysis of nonradioactive DFA using 19F-NMR showed that DFA remained intact in the postischemic reperfusion brain. The present results indicate that 18F-DFA increasingly accumulates in damaged regions of postischemic reperfusion brain.
在缺血再灌注后的大鼠脑中研究了6-脱氧-6-[¹⁸F]氟-L-抗坏血酸（¹⁸F-DFA）的体内摄取和分布情况。通过阻断四条主要动脉，对雄性Wistar大鼠诱导全脑缺血20分钟。在脑缺血大鼠再灌注开始时和再灌注后5天这两个时间点进行¹⁸F-DFA注射。然后在尾静脉注射¹⁸F-DFA后2小时处死大鼠，并测定组织放射性浓度。与假手术对照组相比，在再灌注5天后观察到注射¹⁸F-DFA后，包括大脑皮层、下丘脑和杏仁核在内的特定脑区放射性摄取增加。在使用脑片的体外实验中也获得了类似结果。在组织解剖实验中，在这些脑区观察到了区域缺血后损伤标志物⁴⁵Ca的异常体内蓄积。此外，使用¹⁹F-NMR对非放射性DFA进行代谢物分析表明，DFA在缺血再灌注脑内保持完整。目前的结果表明，¹⁸F-DFA在缺血再灌注脑的受损区域中蓄积增加。
