Taurine and cellular volume regulation in the hippocampus.

Abstract

Taurine is an important osmolyte used for volume regulation in a variety of cell culture systems, including neurons and astroglial cells1–2. Taurine efflux from brain slices and taurine mobilization to the extracellular space of the intact brain appears during exposure to hypoosmotic conditions also suggesting this amino acid is used for brain volume regulation3–4. Taurine contents of isolated cells and brain slice preparations decrease within minutes of exposure to hypoosmolality and other conditions which cause cell swelling. However, little change is observed in brain taurine content of animals exposed to hypoosmotic hyponatremia for several hours5*#x2013;6. Thus, taurine may be redistributed between different cell types of the brain in response to cell swelling. To obtain a better understanding of the role taurine plays in volume regulation of the brain in situ, we examined taurine contents and cellular volume in slices of rat hippocampus during hypoosmotic exposure.