Alterations in Antioxidant Enzyme Activities in Cerebrospinal Fluid Related with Severity of Hypoxic Ischemic Encephalopathy in Newborns

Abstract

Background: The antioxidant status of the tissue affected by ischemia-reperfusion is of great importance for the primary endogenous defense against the free-radical-induced injury. Objective: In this study, we aimed to evaluate the relationship between the activities of antioxidant enzymes [superoxide dismutase (SOD)[, ]glutathione peroxidase (GPX)[, ]and catalase (CAT)] in cerebrospinal fluid (CSF) and severity of hypoxic-ischemic encephalopathy (HIE) in newborns. Methods: Thirty full-term asphyxiated infants (gestational age >37 weeks) and 11 full-term infants (none of whom showed any signs of asphyxia) were included in this study. Activities of SOD, GPX, and CAT in CSF were measured within the first 72 h of life in infants with HIE and controls. Results: Activity of SOD in CSF was significantly higher in infants with HIE compared with controls (p<0.05). GPX and CAT activities were higher in infants with HIE than they were in controls; however, the differences were not statistically significant (p > 0.05). The activities of GPX and CAT were significantly increased in severe HIE as compared with mild HIE and controls (p < 0.05). Conclusion: Both the duration of the hypoxic-ischemic insult and the severity of HIE modulate elevations of enzymatic activity as an adaptive response to excessive free radical production in CSF in newborn infants with HIE. The activities of antioxidant enzyme alterations in CSF correspond highly to the severity of HIE, and these patterns may be useful for diagnostic and prognostic purposes.