Virginia Research Day 2022

Undergraduate Student Research Biomedical

03 CSF And Blood Serum Metabolic Profile Following Blast Exposure

Justin Weatherbee 1 ; Carly Norris 1,2 ; Susan Murphy 2 ; Pamela VandeVord 1,2,3 Corresponding author: justinwbee@vt.edu 1 Virginia Tech, Biomedical Engineering and Mechanics 2 Virginia Tech, School of Biomedical Engineering and Sciences 3 Salem Veterans Affairs Medical Center

at 24 hr significantly decreased and at 48 hr Glutamine significantly increased (p<0.05) following blast exposure compared to sham. The changes in amino acid concentration in the CSF do not provide enough information to make conclusions about the system on its own, however, the fluctuations in Taurine and Glutamine provide promising sensitivity as potential injury markers for mild bTBI. Studies have shown that a decrease in serum Taurine correlates with poorer clinical outcomes following TBI, the mechanism for which warrants further investigation. Additionally, fluctuations in serum Glutamine paired with the tissue response will aid in understanding blood- brain-barrier health. Future work will compare metabolic changes in the brain tissue with the results from CSF and serum in order to better understand how the metabolic regulation across the blood-brain-barrier is affected by mild bTBI.

underwent all procedures but the sham animals were placed adjacent to the ABS and did not receive a blast exposure. Animals were euthanized at 12 hr (n = 5/group), 24 hr (n=8/group), and 48 hr (n=5/group) following treatment and amino acids were extracted from CSF and serum for each time point. High performance liquid chromatography (HPLC) with electrochemical detection was used to measure amino acid concentrations. An internal standard of Tyrosine was used to account for processing losses. External standards showed high sensitivity with an average correlation coefficient of 0.997 +/- 0.006. At 12 hr, the average concentration of Glycine in the CSF showed a trending increase in the blast group compared to the sham group (p<0.1). However, this trend reversed at 24 hr where both CSF Glycine and Glutamine decreased (p<0.1). Additionally, Taurine in the serum

As reported injuries from improvised explosive devices are becoming more prevalent among military populations, blast-induced traumatic brain injury (bTBI) remains a concern. Mild bTBI is most commonly reported resulting in symptoms such as headaches, neurocognitive and motor deficits, PTSD, and depression. There is currently no cure and there is a need to identify potential therapeutic targets or injury markers following mild bTBI. This work aims to identify key metabolic adaptations in the cerebrospinal fluid (CSF) and blood serum by quantifying free amino acid concentrations at time points of 12, 24, and 48 hr following blast exposure. For this study, male Sprague- Dawley rats were exposed to a single blast overpressure with an average magnitude of 17.79 +/- 1.87 psi and duration of 2.39 +/- 0.15 ms in the Virginia Tech Advanced Blast Simulator (ABS). Blast and sham animals

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