Molecular biology of XXXX transporters and their distributions and functions in the brain.

@entity1 @entity20580 @entity2642 @entity2353 @entity859 @entity2036 @entity75 @entity146 @entity63 @entity1313 @entity1372 @entity19 @entity1800 @entity179 @entity7391
@entity7391 and @entity20580 and their derivatives have critical functions and pharmacological applications in the brain. @entity2642 and nucleobases are precursors of @entity2036 , which serve as the energy-rich currency of intermediary metabolism and as precursors of nucleic acids. @entity2642 (e.g., @entity859 ) and @entity2036 are key signaling molecules that modulate brain function through interaction with cell surface receptors. @entity75 involving @entity2642 and their metabolites range from @entity179 and @entity146 conditions to @entity63 . @entity2353 analogs are used clinically in the treatment of @entity1313 and @entity1800 . @entity2642 are hydrophilic molecules, and transportability across cell membranes via specialized @entity2353 transporter (NT) proteins is a critical determinant of their metabolism and, for @entity2353 drugs, their pharmacologic actions. In mammals, there are two types of @entity2353 transport process: bidirectional equilibrative processes driven by chemical gradients, and unidirectional concentrative processes driven by @entity1372 (and proton) electrochemical gradients. In mammals, these processes, both of which are present in brain, are mediated by members of two structurally unrelated membrane protein families (ENT and CNT, respectively). In this Chapter, we review current knowledge of cellular, physiological, pathophysiological and therapeutic aspects of ENT and CNT distribution and function in the @entity1 brain, including studies with NT inhibitors and new research involving NT knockout and @entity19 . We also describe recent progress in functional and molecular studies of ENT and CNT proteins, and summarize emerging evidence of other transporter families with demonstrated or potential roles in the transport of @entity2642 and their derivatives in the brain.
