Effect of cyclooxygenase blockade on the beneficial actions of nicorandil in the stunned myocardium of dogs.

The effects of nicorandil, indomethacin and nicorandil + indomethacin on subendocardial segment shortening (%SS), regional myocardial blood flow and coronary venous thromboxane (TxA2) and prostacyclin (PGI2) levels were compared to those of a saline-treated group in anesthetized dogs subjected to a 15-min coronary artery occlusion and 3 h of reperfusion. During reperfusion, nicorandil markedly improved %SS in the ischemic-reperfused region compared to saline- and indomethacin-treated dogs. Indomethacin did not antagonize the beneficial effects of nicorandil. These results suggest that the beneficial actions of nicorandil in this model are not the result of an increase in PGI2 or decrease in TxA2 synthesis.