Enzymatic Analysis of Oxidatively Modified Proteins in Moderate Traumatic Brain Injury: A Time Dependent Approach

Traumatic brain injury (TBI) affects millions of people worldwide each year. It is harmful, not only due to initial trauma, but also secondary damage. Oxidative stress, due to reactive oxygen and reactive nitrogen species, is one of the major mechanisms investigated in secondary injury of TBI. This creates an imbalance in antioxidants and pro-oxidants in the brain, causing damage to components of the cell including proteins. A moderate TBI model involving Wistar rats was used to analyze enzyme activities of creatine phosphokinase and enolase, essential metabolic enzymes, relative to injured and non-injured samples. Creatine phosphokinase is used as an energy transport shuttle system and provides rapid ATP buffering capacity, thereby acting as an energy reservoir throughout the cell. Enolase, an integral part of the glycolytic pathway, is highly expressed in neuronal cytoplasm. In this experiment, a time dependent treatment model was used. Injured samples were given 150 mg/kg of gamma-glutamyl cysteine ethyl ester (GCEE) or saline, at either 30 minutes or 60 minutes post-injury. The GCEE is an ethyl ester moiety of gamma-glutamyl cysteine, which is a limiting factor in the formation of glutathione, the most potent antioxidant in the brain. This investigation, showing elevated metabolic enzyme activity in GCEE treated samples, further demonstrates the efficacy of GCEE as a possible therapeutic strategy in the treatment of TBI