The Role of Sulphydryl Groups in Efflux of Taurine and Gaba from Cerebral Cortical Cells
A reduction of plasma osmolality due to a fall in Na+ concentration (hyponatraemia) is the disorder of electrolyte homeostasis that is most frequently encountered in clinical medicine32. Hyponatraemia commonly presents as disordered CNS function24. However, ample experimental evidence indicates that brain cells, both in vitro (e. g. cultured preparations) or in vivo, are able to preserve near-normal volumes (fluid contents) when exposed to hyposmotic media. This is accomplished through a reduction of their osmotic potential mediated by loss of inorganic and organic intracellular solutes. The latter comprise mainly straight-chain, aliphatic, non-essential (in most species) amino acids — taurine in particular — and myo-inositol13, 14, 16 and their contribution to the limitation of cell swelling has been quantified in severely hyponatraemic rats31. The role of inorganic ions has been reviewed elsewhere4.
KeywordsOrganic Cation Transport Sulphydryl Group Taurine Release Taurine Efflux Hyposmotic Stress
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