ObjectiveTo use MRI method for continuous observation of the protective effect of uridine 5’-triphosphate (UTP) against cerebral ischemia-reperfusion (IR) injury in rats. MethodsThe cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) in rats. UTP solution was delivered through an indwelling tail venous catheter via microinfusion pump 30 min after MCAO at a rate of 5 ml·kg-1·min-1. Neurological deficit score (NDS) and brain water content were determined 24 h after reperfusion. The infarction volume was determined by 2,3,5-triphenyl-tetrazolium chloride (TTC) staining and MRI at 6, 30, and 54 h after reperfusion. ResultsThe NDS scores in 10, 30, and 90 μg/kg UTP groups were significantly lower than that in the saline control group(P<0.01); the water contents in the right cerebral hemisphere of 10, 30, and 90 μg/kg UTP groups were significantly less than that in the normal saline group(P<0.01). The cerebral infarction volume was gradually decreased with the increase of UTP dose, and the proportions of infarction volumes in 10, 30, and 90 μg/kg UTP groups were significantly decreased compared with the saline control group(P<0.01). The infarction volumes at 6, 30, and 54 h after reperfusion in 90 μg/kg UTP group were significantly lower than those in the saline control group(P<0.01). ConclusionUTP has a protective effect on focal cerebral ischemia-reperfusion injury in rats; it can greatly reduce the volume of cerebral infarction.