Kuge Y, Yajima K, Kawashima H, Yamazaki H, Hashimoto N, Miyake Y
Institute for Biofunctional Research Co., Ltd, Osaka, Japan.
Ann Nucl Med. 1995 Aug;9(3):137-42. doi: 10.1007/BF03165040.
The uptake of octanoate in rat brain and its metabolism were investigated by means of intravenously injecting [1-11C] or [1-14C]octanoate as a tracer. The radioactivity in the cerebrum was increased by an injection of [1-11C]octanoate, and reached its peak level (0.33% ID/g) in about 2 to 5 min, and then decreased slowly. The cerebrum-to-blood ratio of the radioactivity increased with time over a period of 30 min. At 30 sec, [1-11C]octanoate that remained unchanged in the cerebrum accounted for only 8% of the total radioactivity, in spite of there being about 90% in the blood. By means of an injection of [1-14C]octanoate, more than 70% of the total radioactivity in the cerebrum was found to be attributable to radiolabeled glutamate and glutamine at each time point measured between 30 sec and 30 min. The results show that [1-11C]octanoate enters rat brain easily and is trapped in the cerebrum, probably in the form of glutamate and glutamine, and the usefulness of [1-11C]octanoate as a radiopharmaceutical for studying brain fatty acid metabolism by positron emission tomography is therefore suggested.
通过静脉注射[1-11C]或[1-14C]辛酸作为示踪剂，研究了大鼠脑内辛酸的摄取及其代谢情况。注射[1-11C]辛酸后，大脑中的放射性增加，在约2至5分钟内达到峰值水平（0.33%注射剂量/克），然后缓慢下降。在30分钟的时间段内，放射性的脑血比随时间增加。在30秒时，尽管血液中约有90%的[1-11C]辛酸，但大脑中未发生变化的[1-11C]辛酸仅占总放射性的8%。通过注射[1-14C]辛酸，发现在30秒至30分钟之间的每个测量时间点，大脑中总放射性的70%以上归因于放射性标记的谷氨酸和谷氨酰胺。结果表明，[1-11C]辛酸很容易进入大鼠脑内并被困在大脑中，可能是以谷氨酸和谷氨酰胺的形式，因此提示了[1-11C]辛酸作为正电子发射断层扫描研究脑脂肪酸代谢的放射性药物的实用性。
