The 3&agr; isomer of RTI-55, RTI-352, is an effective in vivo binding ligand that reflects greater selectivity for the dopamine transporter than is observed with RTI-55. In addition, there is also a more rapid achievement of apparent equilibrium in the striatal-to-cerebellar ratio (compared to RTI-55) as the ratio peaks at about 30 min and is maintained for about 20 min thereafter. Such apparent equilibrium is useful in developing an approach to measuring the number of dopamine transporters present in tissues. Moreover, these results indicate that the utilization of 3&agr; isomers of a variety of 3&bgr;-(substituted phenyl)tropanes will result in greater selectivity for dopamine transporters and a more rapid of achievement of apparent equilibrium.
RTI-55的3α异构体RTI-352是一种有效的体内结合
配体,反映出对
多巴胺转运体的更大选择性,这种选择性比RTI-55观察到的要高。此外,与RTI-55相比,在纹状体与小脑比率中也更快地达到明显的平衡状态,比率在约30分钟时达到峰值,此后约维持20分钟。这种明显的平衡状态有助于开发一种测量组织中
多巴胺转运体数量的方法。此外,这些结果表明,利用各种3β-(取代苯基)曲梯酮的3α异构体将导致更高的
多巴胺转运体选择性和更快的明显平衡状态的实现。