Effect of hypoosmotic or isoosmotic low [NaCl] medium on amino acid levels measured in the rat cortex <i>in vivo</i>.

Abstract

<p>(a–c) Microdialysis probes, implanted in the rat frontoparietal cortex, were perfused with hypoosmotic medium (−95 mM NaCl, −65% osmolarity) or isoosmotic low NaCl medium (−95 mM NaCl +167 mM mannitol) for one hour. In these experiments, the rat brain was perfused with both the hypoosmotic and isoosmotic medium on opposite sides of the cortex. The data represent average dialysate levels of glutamate (a), aspartate (b), and taurine (c) ±SEM from 5 rats. ** p<0.01, hypoosmotic vs. isoosmotic low [NaCl], repeated measures ANOVA. (d–e) In several experiments dialysate levels of glutamine (d, N = 5), and asparagine (e, n = 3) were additionally measured on the “hypoosmotic” side of the brain.</p