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Volume regulation in astrocytes: A role for taurine as an osmoeffector
Author(s) -
Morales H. Pasantes,
Schousboe A.
Publication year - 1988
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.490200415
Subject(s) - taurine , osmotic concentration , efflux , astrocyte , intracellular , glycine , chemistry , osmoregulation , endogeny , osmotic shock , microbiology and biotechnology , medicine , biology , biochemistry , endocrinology , amino acid , central nervous system , ecology , salinity , gene
Astrocytes in culture regulate their volume under anisosmotic conditions by as yet unclear mechanisms. In a number of other cells this process involves a loss of intracellular osmotically active solutes, including taurine. The possibility that taurine participates as an osmoeffector in astrocytes was examined in cultured astrocytes exposed to hyposmolar conditions. Astrocytes responded to decreases in osmolarity by rapid swelling followed by a volume regulatory phase. Hyposmotic conditions induced a dramatic increase of 3 H‐taurine efflux, with a time course corresponding to the cell volume regulatory phase. Decreasing osmolarity from 310 to 254, 198 or 150 m osmoles resulted in the release of 8.2%, 17%, and 54%, respectively, of 3 H‐taurine previously accumulated by astrocytes. Endogenous taurine concentration decreased 64%. The efflux of 3 ‐H GABA, 3 H‐glycine, or 3 H‐D‐aspartate was much less affected under similar conditions. These results suggest a role for taurine as an osmoeffector in astrocytes.