Localization of taurine transporters, taurine, and (3)H taurine accumulation in the rat retina, pituitary, and brain.
The nervous system contains an abundance of taurine, a neuroactive sulfonic acid. Antibodies were generated against two cloned high-affinity taurine transporters, referred to in this study as TAUT-1 and TAUT-2. The distribution of such was compared with the distribution of taurine in the rat brain, pituitary, and retina. The cellular pattern of [(3)H] taurine uptake in brain slices, pituitary slices, and retinas was examined by autoradiography. TAUT-2 was predominantly associated with glial cells, including the Bergmann glial cells of the cerebellum and astrocytes in brain areas such as hippocampus. Low-level labeling for TAUT-2 was also observed in some neurones such as CA1 pyramidal cells. TAUT-1 distribution was more limited; in the posterior pituitary TAUT-1 was associated with the pituicytes but was absent from glial cells in the intermediate and anterior lobes. Conversely, in the brain TAUT-1 was associated with cerebellar Purkinje cells and, in the retina, with photoreceptors and bipolar cells. Our data suggest that intracellular taurine levels in glial cells and neurons may be regulated in part by specific high-affinity taurine transporters. The heterogeneous distribution of taurine and its transporters in the brain does not reconcile well with the possibility that taurine acts solely as a ubiquitous osmolyte in nervous tissues.
Pow
David V
DV
Department of Physiology and Pharmacology, School of Biomedical Sciences, University of Queensland, Brisbane, Australia. d.pow@mailbox.uq.edu.au
Sullivan
Robert
R
Reye
Peter
P
Hermanussen
Siobhan
S
D026921:Amino Acid Transport Systems, Neutral / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002352:Carrier Proteins / Q000187:drug effects / Q000378:metabolism*; D002531:Cerebellum / Q000187:drug effects / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D027342:Excitatory Amino Acid Transporter 2 / Q000378:metabolism; D050487:Glycine Plasma Membrane Transport Proteins; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D007150:Immunohistochemistry; D008562:Membrane Glycoproteins / Q000187:drug effects / Q000378:metabolism*; D026901:Membrane Transport Proteins; D009457:Neuroglia / Q000187:drug effects / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009830:Olfactory Bulb / Q000187:drug effects / Q000378:metabolism; D010902:Pituitary Gland / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D012160:Retina / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D013654:Taurine / Q000378:metabolism*; D000099247:Taurine Transporters
D026921:Amino Acid Transport Systems, Neutral; D002352:Carrier Proteins; D027342:Excitatory Amino Acid Transporter 2; D050487:Glycine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D013654:Taurine; D000099247:Taurine Transporters