Mechanisms of transport of nucleosides and nucleoside analogues in choroid plexus.

Nucleoside and nucleobase analogues are being used to treat a number of viral infections of the central nervous system (CNS) including herpes-simplex encephalitis, cytomegalovirus retinitis, and AIDS-related dementia complex. Delivery of nucleoside analogues to the CNS is considered a key challenge in the treatment of these diseases. In this review, we focus on the mechanisms of transport of nucleosides and nucleoside analogues in the choroid plexus. First, the structure and function of the choroid plexus are reviewed. Then, we focus on the mechanisms of nucleoside transport in mammalian cells. Specific emphasis is placed on the molecular and functional characteristics of various nucleoside transporters. A discussion is then devoted to the mechanisms of nucleoside transport in choroid plexus. Current knowledge of nucleoside transport systems in choroid plexus in several animal species is summarized followed by a short section on the mechanisms of transport of nucleobases in the choroid plexus. Finally, a brief section on future directions is included.