Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2010, Vol. 21 ›› Issue (3): 171-176 doi: 10.13538/j.1001-8042/nst.21.171-176

• RADIOCHEMISTRY, RADIOPHARMACEUTICALS AND NUCLEAR MEDICIN • Previous Articles     Next Articles

Radio-ligand receptor binding assay in vitro and animal biodistribution in vivo of 99Tcm-N-ethyl-N2S2-memantine as a potential NMDA receptor imaging agent

LIU Yingtao1 ZHOU Xingqin2 CAO Guoxian2,* ZHANG Jiankang2 QIN Xiaofeng2 XU Xijie2 ZOU Meifen2   

  1. 1 Jiangnan University, School of Medicine and Pharmaceutics, Wuxi 214122, China 2 Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China
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LIU Yingtao, ZHOU Xingqin, CAO Guoxian, ZHANG Jiankang. Radio-ligand receptor binding assay in vitro and animal biodistribution in vivo of 99Tcm-N-ethyl-N2S2-memantine as a potential NMDA receptor imaging agent.Nuclear Science and Techniques, 2010, 21(3): 171-176     doi: 10.13538/j.1001-8042/nst.21.171-176

Abstract:

The pharmacologic characteristics of 99Tcm-N-ethyl-N2S2-memantine, an NMDA receptor imaging agent, was investigated. It was prepared by a one-step reaction from N-ethyl-N2S2-memantine. The affinity and specificity were determined by radio-ligand receptor binding assay (RRA). Biodistribution in vivo in mice was performed. The results showed that 99Tcm-N-ethyl-N2S2-memantine bound to a single site on NMDA receptor with a Kd of 584.32 nmol/L and a Bmax of 267.05 nmol/mg. A competitive analysis showed that such specific binding could be inhibited by specific inhibitors of NMDA receptor, such as ketamine and (+)-MK-801. The biodistribution exhibited rapid uptake and favorable retention in mice brains. The major radioactivity was metabolized by the hepatic system. A two-compartment model of C = 4.49e–0.083t + 1.42e–0.0016t was established, and the half life was 8.35 min in blood. In conclusion, the new radio-ligand 99Tcm-N-ethyl-N2S2-Memantine has a moderate affinity and specific binding to NMDA receptor, and can easily cross the blood-brain barrier (BBB). Therefore, it may be a potential NMDA receptor imaging agent.

Key words: 99Tcm-N-ethyl-N2S2-memantine, NMDA receptor, Radio-ligand receptor binding assay, Biodistribution, imaging