Effect of the prostacyclin analogue, iloprost, on infarct size after permanent focal cerebral ischemia

This investigation was undertaken to study the effect of iloprost, a stable analogue of prostacyclin, on infarct size after permanent focal cerebral ischemia in the rabbit. Forty-two adult rabbits were subjected to left middle cerebral artery occlusion via the transorbital route. Fourteen rabbits received an intravenous (IV) infusion of 30 μg/kg iloprost, 7 rabhits received an IV infusion of 10 μg/kg, and 9 rabbits received an IV infusion of 20 μg/kg iloprost. Twelve rabbits received an intravenous infusion of saline. Treatment with iloprost started immediately after middle cerebral artery occlusion and continued for 1 h. After killing the animals, brains were removed and five coronal slices were incubated in a 2,3,5-triphenyltetrazolium chloride solution to determine the infarct size. Treatment with 30 μg/kg iloprost significantly reduced the infarct size compared with treatment with saline (3.49 ± 2.79% vs. 9.03 ± 4.26%, P<0.001), but the lower doses of iloprost did not have a beneficial effect on the size of the infarct. These results suggest that intravenous iloprost treatment after occlusion has a highly protective effect without any side effects such as hypotension.