Opposite Effects of Extracellular Sodium Removal on the Uptake of Tryptophan into Rat Cortical Slices and Synaptosomes

Abstract
The removal of extracellular sodium decreased L-tryptophan (L-TRP) uptake into brain slices but increased uptake into synaptosomes. The uptake of 5-hydroxytryptamine (5-HT) was inhibited in both preparations under these conditions. It is suggested that the different effects on L-TRP uptake may be due to differences in cellular composition between the two preparations rather than to any differences in sample handling.