Development of New Noninvasive Methods of Functional Imaging Using Biologically Active Substances Labelled with Positron Emitting Radionuclides

1. 化学研究[氟乙酰基-^<18>F]氟褪黑素(1)的有效合成已经建立。所需同位素(1)的放射化学产率为26.7%。合成的纯度、比活性和总合成时间分别为0.98%、540mCi/mmol和0.90 min。N^< ω >-[^<18>F]氟乙酰血清素(2)也在类似条件下以22.6%的放射化学产率合成。该激素(2)的纯度和比活性分别为98.0%和600mCi/mmol。医学研究我们已经研究了正电子标记放射性药物用于功能成像的可行性。(1)的组织分布已经用小鼠进行了研究。其分布与先前报道的碘标记褪黑素相似。提示：(1)可能是研究褪黑素代谢与昼夜节律相关性的有用示踪剂(2)。我们用N-[^<18>F]氟乙酰- d -氨基葡萄糖(3)研究了肿瘤PET成像。糖(3)经耳静脉注射到大腿VX2肿瘤的日本大白兔，并进行PET成像。(3)肿瘤清晰可见。临床PET研究证实2-脱氧-2-[^<18>F]氟- d -半乳糖检测肝癌肝外转移的有效性。

1. Chemical ResearchAn efficient synthesis of[fluoroacetyl-^<18>F]fluoromelatonin (1) has been established. The desired isotope (1) was obtained in a 26.7% radiochemical yield. The purity, specific activity and the total time required for its synthesis are>98%, 540mCi/mmol and ca.90 min, respectively. N^<omega>-[^<18>F]Fluoroacetylserotonin (2) was also synthesized under similar conditions in 22.6% radiochemical yield. The purity and specific activity of the hormone (2) are>98% and 600mCi/mmol, respectively.2. Medical ResearchWe have examined the feasibility of positron labelled radiopharmaceuticals for functional imaging.(1). Tissue distribution of (1) has been studies using mice. The distribution was similar to that of iodolabelled melatonin which has been reported previously. It is suggested that (1)may be a useful tracer for studying the correlation of melatonin metabolism and circadian rhythm.(2). We have studied the tumor imaging with PET using N-[^<18>F]Fluoroacetyl-D-glucosamine(3). Sugar(3) was intravenously injected through the ear vein to a Japanese white rabbit bearing a VX2 tumor in the thigh, and PET imaging was performed. Tumor was clearly visualized using (3).(3) .Clinical PET sudy demonstrated the usefulness of 2-Deoxy-2-[^<18>F]fluoro-D-galactose for the detection of extrahepatic metastasis of hepatoma.