Influence of indomethacin on an increase in cerebral blood flow induced by KC-404, a novel cerebral vasodilator, in an anesthetized dog

The effect of KC-404 on vertebral blood flow in the absence and presence of indomethacin was investigated in an anesthetized dog. KC-404 (0.2 mg/kg, i.v.) showed a significant and long lasting increase in vertebral blood flow. This was markedly diminished by pretreatment of the animal with indomethacin. The increase in heart rate due to KC-404 administration was also diminished, though moderately, by pretreatment with indomethacin. From these results, the possible mechanism of action of KC-404 was discussed, particularly in reference to cerebral vasodilating prostaglandins.