The influence of the intracellular concentration of sodium on the uptake of L-( 14 C)valine by chopped tissue from cerebral cortex.

1. The intracellular concentrations of sodium, potassium, ATP and creatine phosphate in chopped tissue from guinea-pig cerebral cortex were altered by a 10min period of electrical stimulation. 2. The ability of the tissue to take up l-[(14)C]valine and incorporate it into protein was tested at various times after the cessation of electrical stimulation. 3. The restoration of the ability of the tissue to accumulate l-[(14)C]valine correlated closely with the restoration of the resting intracellular concentrations of sodium and ATP.