Ann Thorac Surg 1995;59:584
© 1995 The Society of Thoracic Surgeons
Discussion
Discussion
See also page 579.
DR THOMAS M. EGAN (Chapel Hill, NC): That was an excellent presentation. I have a couple of questions that might be germane to interpreting your data. Have you had any experience with antioxidants or other agents that might reduce injury in this setting? Is it possible that the agent that you have used has antioxidant properties and that your receptor-agent interaction is simply a method of localizing an antiinflammatory agent to a site of injury?
DR REDMOND: Doctor Egan, this is certainly a very interesting concept of the mechanism of action of glutamate receptor antagonists. In am unaware of any data to date that suggest that glutamate receptor antagonists have any antioxidant properties. Although oxygen free radical generation is a part of the cascade of cellular events that leads to neuronal injury during glutamate excitotoxicity, beyond antagonizing the glutamate receptors, glutamate antagonists have not been shown to be antioxidants or scavenge free radicals in any in vitro or in vivo paradigms to date. We have not used other antioxidants in our particular model of hypothermic circulatory arrest because we are concentrating on the prevention of a delayed neuronal injury secondary to excitotoxicity as opposed to a putative reperfusion and oxygen free radical–mediated neurologic injury.
DR DONALD C. WATSON, JR (Memphis, TN): Have you given any thought as to how this might be extended to the operating room?
DR REDMOND: Yes, in fact, Dr Watson, we currently are developing plans to use glutamate receptor antagonists in the clinical arena. The antagonists that we have used in our canine model to date are not suitable for human use, but there are several AMPA receptor and NMDA receptor antagonists that should be available within the next 12 to 18 months that can be used safely in the clinical setting. Once we have completed our studies to identify the most comprehensive battery of neuropsychologic tests, together with the most meaningful and efficient means of following up neurologic function during the cardiac surgical procedure and the early postoperative period, we expect to use a variety of these drugs for cardiac patients who we can confidently predict are at high risk for neurologic complications after hypothermic circulatory arrest and prolonged cardiopulmonary bypass.
Related Article
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AMPA Glutamate Receptor Antagonism Reduces Neurologic Injury After Hypothermic Circulatory Arrest
- J. Mark Redmond, Kenton J. Zehr, Mary E. Blue, Mary S. Lange, A. Marc Gillinov, Juan C. Troncoso, Duke E. Cameron, Michael V. Johnston, and William A. Baumgartner
Ann. Thorac. Surg. 1995 59: 579-584.
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