Effects of inhibitory amino acids on adenosine release in the mouse hippocampus.

Adenosine is a neuromodulator which inhibits the synaptic release of neurotransmitters. However, only little is known of the effects of inhibitory neurotransmitters and modulators on adenosine release. We studied these effects with hippocampal slices from developing (7-day-old) and young adult (3-month-old) mice under normoxic and ishemic conditions. In normoxia, adenosine release was about 3-fold greater in adults than in developing mice. beta-Alanine and L-serine (both 0.1 mM) significantly reduced the release of [3H]adenosine in normoxia in developing mice. Glycine, beta-Alanine and L-serine (all 0.1 mM) had similar effects in ischemia. Taurine depressed concentration- dependently the release in developing mice but had no effect in adults. The simultaneous release of taurine and adenosine may constitute an important protective mechanism under ischemic conditions.