Pentoxifylline in Regional Cerebral Ischemia in Cats

The effect of pentoxifylline on regional cerebral ischemia was evaluated in 22 cats. In one group of 10 cats the middle cerebral artery (MCA) was occluded by a transorbital approach, and the cats were maintained on an intensive care protocol for 48 h. Pentoxifylline 10 mg.kg-1 initiated intravenously 30 min post-occlusion and followed by 6.3 mg.kg-1.h-1 for 48 h failed improve the neurologic outcome or infarct size when compared to controls. In another group of 12 cats with the same ischemic lesion, regional cerebral blood flow in the anterior (ischemic) area and an ipsilateral parieto-occipital region was measured by 133Xe wash-out after intra-arterial injection. MCA occlusion reduced the anterior flow by 50% from a mean control value of 62.7 ml.100 g-1.min-1 to 31.9 ml.100 g-1.min-1. The parieto-occipital flow was reduced by 20-30%, probably due to diaschisis. Pentoxifylline produced only a brief, although approximately 50%, increase in flow detected over both brain regions and failed to improve the cerebral energy stores as measured 150 min following MCA occlusion. From the neurologic, blood flow and metabolic data, it is concluded that pentoxifylline failed to affect cerebral ischemia favorably in cats.