Sodium Pyruvate Reduced Hypoxic-Ischemic Injury to Neonatal Rat Brain

BACKGROUND: Neonatal hypoxia-ischemia (HI) remains a major cause of severe brain damage and is often associated with high mortality and lifelong disability. Immature brains are extremely sensitive to hypoxia-ischemia, shown as prolonged mitochondrial neuronal death. Sodium pyruvate (SP), a substrate of the tricarboxylic acid cycle and an extracellular antioxidant, has been considered as a potential treatment for hypoxic-ischemic encephalopathy (HIE), but its effects have not been evaluated in appropriate animal models for hypoxic-ischemic encephalopathy (HIE). METHODS: This investigation employed primary cortical neuron cultures derived from neonatal rats subjected to oxygen and glucose deprivation (OGD) and a well-established neonatal rat hypoxia-ischemia model. RESULTS: HI caused brain tissue loss and impaired sensorimotor function and spatial memory while SP significantly reduced brain damage and improved neurological performance. These neuroprotective effects of SP are likely the result of improved cerebral metabolism as demonstrated by maintaining ATP levels and preventing an increase in intracellular reactive oxygen species (ROS) levels. SP treatment also decreased levels of Bax, a death signal for immature neurons, blocked caspases-3 activation, and activated a key survival signaling kinase, Akt, both in vitro and in vivo. CONCLUSION: SP protected neonatal brain from hypoxic-ischemic injury through maintaining cerebral metabolism and mitochondrial function.