Functional and cytoarchitectural spinal cord protection by ATL-146e after ischemia/reperfusion is mediated by adenosine receptor agonism
| Autor: | Carlos Tache-Leon, John A. Kern, Thomas S. Maxey, T. Brett Reece, Joel Linden, Peter I. Ellman, Irving L. Kron, David O. Okonkwo, Jeffrey J. Laurent, Curtis G. Tribble |
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| Rok vydání: | 2006 |
| Předmět: |
Time Factors
Adenosine A2 Receptor Agonists Cyclohexanecarboxylic Acids Receptor Adenosine A2A Cell Survival Ischemia Pharmacology Neuroprotection medicine Animals Receptor Neurons Paraplegia business.industry Spinal Cord Ischemia Triazines Antagonist Triazoles medicine.disease Spinal cord Adenosine receptor Adenosine A2 Receptor Antagonists Disease Models Animal medicine.anatomical_structure Neuroprotective Agents Spinal Cord Purines Anesthesia Reperfusion Injury Immunohistochemistry Surgery Rabbits business Cardiology and Cardiovascular Medicine Reperfusion injury Microtubule-Associated Proteins |
| Zdroj: | Journal of vascular surgery. 44(2) |
| ISSN: | 0741-5214 |
| Popis: | BackgroundATL-146e protects the spinal cord from ischemia/reperfusion injury, presumably via adenosine A2A receptor activation, but this relationship remains unproven. We hypothesized that spinal cord functional and cytoarchitectural preservation from ATL-146e would be lost with simultaneous administration of the specific adenosine A2A antagonist ZM241385 (ZM), thus proving that adenosine A2A receptor activation is responsible for the protective effects of this compound.MethodsNew Zealand White rabbits underwent 45 minutes of infrarenal aortic cross-clamping. Groups (n = 10) included sham, ischemia, ischemia plus ATL-146e (ATL-146E), ischemia plus ZM, or ischemia with both compounds (agonist-antagonist). Tarlov scores were recorded every 12 hours. After 48 hours, the spinal cord was fixed for histology and microtubule-associated protein 2 immunohistochemistry.ResultsTarlov scores at 48 hours were significantly better in the sham and ATL-146E groups (5.0 and 3.9, respectively) compared with the other three groups (all ≤1.3; P < .001). On hematoxylin and eosin, neuronal viability was higher in the sham, ATL-146E, and agonist-antagonist groups compared with the control and ZM groups (P < .05). Microtubule-associated protein 2 expression was preserved in the sham and ATL-146E groups but was lost in the ATL + ZM, ZM241385, and control groups.ConclusionsATL-146e preserves the spinal cord in terms of both cytoarchitecture and function after reperfusion of the ischemic spinal cord, but this preservation is not completely blocked by competitive adenosine A2A receptor antagonism. Although ATL-146e does seem to partially function through activation of the adenosine A2A receptor, the neuroprotective mechanism may not be limited to this particular receptor.Clinical RelevanceParaplegia remains a real and devastating complication of vascular procedures that involve the thoracic aorta. Pharmacologic intervention has not yet had the proven success of other surgical adjuncts in limiting this complication, but treatment with adenosine analogues at reperfusion has shown promise in animal models. This study examined the specificity of the neuroprotective qualities of an adenosine receptor agonist in the setting of spinal cord ischemia/reperfusion injury with the ultimate goal of preventing neurologic complications in this specific subset of vascular patients. |
| Databáze: | OpenAIRE |
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