Chloride ions, potassium stimulation and release of endogenous taurine from cerebral cortical slices from 3 day old and 3 month old mice.
The release of endogenous taurine from superfused cerebral cortical slices from 3 day old and 3 month old mice was studied in media in which chloride ions were equimolarly replaced by the permeant anion acetate or the impermeant anion gluconate and in media supplemented by 50 mM potassium ions. Potassium stimulation in iso-osmotic media released much more taurine from slices from 3 day old than 3 month old mice. The release was substantially attenuated in hyperosmotic medium in 3 day olds but not in 3 month olds. The results were the same in media in which the potassium ion and chloride ion product was kept constant. Taurine release was enhanced by omission of chloride ions. The enhancement was greater in 3 day olds when acetate was the replacer but not in 3 month olds. In the immature brain, but not in the mature brain, the cell volume regulation seems to be responsible for a major part of the evoked taurine release, which is reminiscent of the properties of taurine release from cultured astrocytes and neurons.
Oja
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SS
Tampere Brain Research Center, Department of Biomedical Sciences, University of Tampere, Finland.
Saransaari
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P
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D002540:Cerebral Cortex / Q000378:metabolism*; D002712:Chlorides / Q000494:pharmacology*; D003470:Culture Media; D066298:In Vitro Techniques; D051379:Mice; D008815:Mice, Inbred Strains; D011188:Potassium / Q000494:pharmacology*; D013654:Taurine / Q000378:metabolism*
D002712:Chlorides; D003470:Culture Media; D013654:Taurine; D011188:Potassium