Activation of Pyruvate Dehydrogenase Activity Bydichloroacetate Improves Survival and Neurologic Outcomes After Cardiac Arrest in Rats
No pharmacological interventions are currently available to provide neuroprotection for patients suffering from cardiac arrest. Dichloroacetate (DCA) is a pyruvate dehydrogenase kinase inhibitor, which activates pyruvate dehydrogenase (PDH), and increases cell adenosine triphosphate (ATP) production by promoting influx of pyruvate into the Krebs cycle. In this study, we investigated the effects of DCA on post-resuscitation neurological injury in an asphyxial cardiac arrest rat model. Asphyxial cardiac arrest was established by endotracheal tube clamping. A total of 111 rats were randomized into 3 groups: Sham group, Control group and DCA intervention group. Animals in DCA intervention group were intraperitoneally administered DCA with a loading dose of 80 mg/kg at 15 minutes after return of spontaneous circulation (ROSC), whereas rats in the Control group received equivalent volume of saline. DCA treatment increased 3-day survival time, and reduced neurologic deficit scores at 24, 48 and 72 hours after ROSC. It also attenuated cellular apoptosis and neuronal damage in the hippocampal cornuammonis 1 region by hematoxylin-eosin staining and TdT-mediated dUTP nick-end labeling assay. In addition, DCA reduced the messenger RNA expression of TNF-α and IL-1β in brain hippocampus and cortex after ROSC. Furthermore, DCA treatment significantly increased ATP production, PDH activity, and decreased blood glucose, lactate and brain pyruvate levels after ROSC. Our results suggested that DCA has neuroprotective effects on brain injury after cardiac arrest, and its salutary effects were associated with an increase of mitochondrial energy metabolism in the brain through activation of PDH activity.