Neuroprotective Effect of Long-term MgSO4 Administration After Cerebral Hypoxia-Ischemia in Newborn Rats Is Related to the Severity of Brain Damage

Previous studies have shown contradictory results regarding magnesium-mediated neuroprotection in animal models of perinatal asphyxia. The aim of this study is to investigate the e fects of MgSO 4 postasphyxial treatment on hypoxia-ischemia (HI)—induced brain injury in neonatal rats and the possibility that this e fect is related to the severity of brain damage. Seven-day-old rats underwent unilateral carotid artery ligation followed by 1 or 2 hours of hypoxia (8% O 2 ) and MgSO 4 administration. Adenosine triphosphate/phosphocreatine and glutamate/glutamine measurements and neuropathological evaluation of the hippocampus were used to assess the e fects of HI and MgSO 4 . HI caused time-dependent changes in energy stores, amino acid concentrations, and brain damage. Administration of MgSO 4 after 1 hour but not after 2 hours of hypoxia resulted in significant prevention of HI-induced brain injury. MgSO 4 administration results in a significant protection against moderate HI-induced brain damage, whereas it fails to offer a similar effect against severe brain damage.