RELAXANT EFFECTS ON ILOPROST IN CANINE-CEREBRAL ARTERY

Iloprost caused relaxation of rings of canine cerebral arteries precontracted with prostaglandin F2-alpha or the thromboxane A2 analogue U46619, but it was without effect on arteries precontracted with potassium chloride. Pretreatment with iloprost did not significantly affect the concentration-response curve to any agent. Contractile responses to oxyhemoglobin were completed relaxed by iloprost. In arteries from animals with moderate cerebrovascular spasm, the response to prostaglandin F2-alpha. was also reduced by iloprost. The observation that iloprost relaxes the response to oxyhemoglobin to prostaglandin F2-alpha in spastic arteries may be of interest in the management of cerebral vasospasm.