Suehiro M, Dannals R F, Scheffel U, Stathis M, Wilson A A, Ravert H T, Villemagne V L, Sanchez-Roa P M, Wagner H N
Div. of Nuclear Medicine and Radiation Health Sciences, Johns Hopkins Medical Institutions, Baltimore, MD 21205-2179.
J Nucl Med. 1990 Dec;31(12):2015-21.
A new dopamine D2 receptor radiotracer, N-11C-methyl-benperidol (11C-NMB), was prepared and its in vivo biologic behavior in mice and a baboon was studied. Carbon-11-NMB was determined to bind to specific sites characterized as dopamine D2 receptors. The binding was saturable, reversible, and stereospecific. Kinetic studies in the dopamine D2 receptor-rich striatum showed that 11C-NMB was retained five times longer than in receptor-devoid regions, resulting in a high maximum striatal-to-cerebellar ratio of 11:1 at 60 min after injection. From frontal cortex and cortex, on the other hand, the tracer washed out as rapidly as it did from cerebellum, resulting in tissue-to-cerebellar ratios close to one in these regions at any time after injection. Blocking studies confirmed the specificity and selectivity of the 11C-NMB binding to the dopamine D2 receptor. A PET study with 11C-NMB of the baboon brain revealed highly selective labeling of dopamine D2 receptor sites which was blocked by preinjection of raclopride.
制备了一种新型多巴胺D2受体放射性示踪剂N-11C-甲基苯哌利多（11C-NMB），并研究了其在小鼠和狒狒体内的生物学行为。确定碳-11-NMB与被表征为多巴胺D2受体的特异性位点结合。这种结合具有饱和性、可逆性和立体特异性。在富含多巴胺D2受体的纹状体中进行的动力学研究表明，11C-NMB的保留时间比在缺乏受体的区域长5倍，在注射后60分钟时，纹状体与小脑的最大比值高达11:1。另一方面，从额叶皮质和皮质来看，示踪剂的清除速度与从小脑清除的速度一样快，在注射后的任何时间，这些区域的组织与小脑的比值都接近1。阻断研究证实了11C-NMB与多巴胺D2受体结合的特异性和选择性。一项用11C-NMB对狒狒大脑进行的PET研究显示，多巴胺D2受体位点有高度选择性标记，预先注射雷氯必利可阻断这种标记。
