Ann Thorac Surg 1996;61:1707
© 1996 The Society of Thoracic Surgeons
Discussion
Discussion
See also page 1699.
DR ALDEN H. HARKEN (Denver, CO): I think this is very exciting stuff. Lots of people are now using nitric oxide as a direct vasodilator, and as far as I know it dilates everything everyplace. However, the other potential putative mechanism is that with any kind of stress or stimulus, what you are doing is upregulating adhesion receptors both on the endothelial cell and on neutrophils. You have very nicely demonstrated that if you give arginine, you may well promote the nitric oxide pathway, which could either directly vasodilate or, as was demonstrated by Dave Fullerton yesterday, downregulate these adhesion molecules, decreasing neutrophil adherence and therefore unclogging some of those cerebral blood vessels. My question, therefore, is did you look to see whether there was any neutrophil accumulation or look to see whether any of the circulating neutrophils were expressing some of their adhesion molecules with and without arginine or with and without nitric oxide?
Again, I think this is important stuff.
DR TSUI: Thank you for your comments. The answer to your question is no, we did not attempt to look at the actual cellular mechanism in this study. There is no doubt that the injury mechanism of circulatory arrest is very complex and multifactorial. The damage probably results from a combination of ischemia and reperfusion. From these studies alone, we found that the production of nitric oxide was reduced in the cerebral circulation after hypothermic circulatory arrest, but I am afraid that I cannot tell you where the actual site of injury lies. Further studies are being carried out in our laboratory to look into the cellular mechanisms of injury.
Related Article
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Nitric Oxide Production Affects Cerebral Perfusion and Metabolism After Deep Hypothermic Circulatory Arrest
- Steven S. L. Tsui, Paul M. Kirshbom, Michael J. Davies, Michael T. Jacobs, William J. Greeley, Frank H. Kern, J. William Gaynor, and Ross M. Ungerleider
Ann. Thorac. Surg. 1996 61: 1699-1707.
[Abstract]
[Full Text]
