The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Jan 2014
Dexmedetomidine, an α-2a adrenergic agonist, promotes ischemic tolerance in a murine model of spinal cord ischemia-reperfusion.
Dexmedetomidine, an α-2a adrenergic agonist, given pre- and postoperatively was previously shown to attenuate neuronal injury in a murine model of spinal cord ischemia-reperfusion. In the brain, α-2 agonists have been shown to induce the phosphorylation of cyclic AMP response-element binding protein (CREB), a transcription factor necessary for neuron survival. We hypothesized that the α-2a adrenergic agonist given preoperatively increases CREB-mediated neuroprotective proteins, attenuating neuronal injury and cytoarchitectural decay. ⋯ Pretreatment with the α-2a agonist dexmedetomidine preserved neurologic function and attenuated neuronal injury following thoracic aortic occlusion in mice. This relationship was associated with an increased phosphorylation of protein kinase B and CREB and subsequent up-regulation of antiapoptotic factor B-cell lymphoma 2 and brain-derived neurotrophic factor. Thus, α-2a receptor agonism-induced CREB phosphorylation and contributes to dexmedetomidine's protective mechanism in the spinal cord following ischemia.