Neuronal (Na+,K+)-ATPase and the release of purines from mouse and rat cerebral cortex

Slices of mouse or rat cerebral cortex were incubated with [3H]adenine or [3H]adenosine, and [14C]GABA. Purines and GABA could subsequently be released by ouabain. The release of purines previously shown to occur on restoring elevated K+ levels to normal was not mimicked by noradrenaline at concentrations which activate (Na+,K+)-ATPase. Potassium-free solutions evoked no release of purine during the test period, but resulted in a large release when K+ was restored to normal. K+-free solutions evoked an immediate release of GABA. It is concluded that (Na+,K+)-ATPase is not involved in purine release.