Effect of adenosine on adenosine triphosphate-sensitive potassium channel during hypoxia in rat hippocampal neurons.

Using the whole-cell patch clamp method, we explored the effect of adenosine on the K(ATP) current and its regulatory mechanisms in acutely dissociated rat hippocampal neurons. A chemical hypoxia model was made using 0.2 mmol/l 2,4dinitrophenol (2,4DNP). During hypoxia, the K(ATP) current was not raised significantly by adenosine alone, but was accelerated significantly by adenosine in combination with the selective A(2) receptor blocker 3, 7-dimethl-1-propargylxanth-ine. The selective A(1) receptor agonist N6-cyclopentyladenosine also accelerated the K(ATP) current. These results suggest that activation of the adenosine A(1) receptor can accelerate opening of the K(ATP) channel during hypoxia, and that the A(2) receptor may have an opposing effect to the A(1) receptor.