Abstract: Objective To investigate the effect of ethyl pyruvate (EP) on the expression of caspase-3 in the hippocampus and the learning and memory ability in neonatal rats with hypoxic ischemic brain damage (HIBD). Methods 90 Wistar rats of 7 days old were randomly divided into sham operation group (n=15), HIBD group (n=15), EP1 group (n=15, 10 ml/kg), EP2 group (n=15, 30 mg/kg), EP3 group (n= 15, 50 mg/kg) and EP4 group (n=15, 100 mg/kg). The model was established with Rice's method. 30 minutes before operation, and every 24 hours after operation, EP groups were injected with 10 ml/kg, 30 mg/kg, 50 mg/kg, 100 mg/kg EP in abdomen respectively, for 2 weeks. After treatment, the caspase-3 positive cells were observed by immunohistochemical staining, and the latency and the times crossing the target quadrant were tested by Morris water maze test. Results The caspase-3 positive cells were less in EP groups than in HIBD group (P<0.05), expect EP1 group (P>0.05), especially in EP3 group (P<0.01). The latency and the times crossing the target quadrant were better in EP groups than in HIBD group (P<0.05), expect EP1 group (P>0.05), especially in EP3 group (P<0.01). Conclusion Ethyl pyruvate can decrease the expression of caspase-3 in hippocampus, and improve the ability of memory and learning in neonatal rats with HIBD.

Key words: hypoxic ischemic brain damage, ethyl pyruvate, caspase-3, learning and memory, rats