Endogenous adenosine delays the onset of hypoxic depolarization in the rat hippocampus in vitro via an action at A sub(1) receptors

The effect of endogenous adenosine on the delay to hypoxic depolarization (HD) was examined utilizing in vitro slices of gerbil hippocampus. Adenosine receptor antagonists were used to block the actions of adenosine during hypoxia, and the delay to HD was measured in the CA1 region. Both a broad spectrum antagonist (theophylline) and an A sub(1) receptor-specific antagonist (8-cyclopentyl-1,3-dimethylxanthine; CPT) shortened the delay to HD. These findings indicate that endogenous adenosine working through A sub(1) receptors prolongs the delay to HD. This effect may contribute to the neuroprotective influence of adenosine and its analogs.