Evoked release of endogenous adenosine from rat cortical slices by K+ and glutamate.

Release of endogenous adenosine from rat cortical slices was determined in response to depolarization by 30 mM K+ and by exposure to glutamate. K+ and glutamate both released adenosine. Glutamate-evoked release was decreased by approximately 50% in the presence of the N-methyl-D-aspartate (NMDA) receptor antagonist, 2-amino-5-phosphonovaleric acid (APV). The adenosine released by glutamate could modulate neurotransmission, and may have a protective effect in pathologic conditions of excess excitation involving glutamate.