Influence of the ph of cardioplegic solutions on cellular energy metabolism and hydrogen ion flux during neonatal hypothermic circulatory arrest and reperfusion: A dynamic 31p nuclear magnetic resonance study in a pig model
| Autor: | George M. Alfieris, Michael A. Portman, David Anderson, Yun Xiao, Anthony L. Panos, Flavian M. Lupinetti, Xue-Han Ning |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Pulmonary and Respiratory Medicine
Cardiac function curve medicine.medical_specialty Magnetic Resonance Spectroscopy Phosphocreatine Swine Intracellular pH Myocardial Reperfusion Injury Ion Channels chemistry.chemical_compound Adenosine Triphosphate Hypothermia Induced Internal medicine Animals Medicine Cardioplegic Solutions business.industry Myocardium Metabolism Hydrogen-Ion Concentration Hypothermia Cytosol Endocrinology Animals Newborn chemistry Anesthesia Circulatory system Heart Arrest Induced Surgery medicine.symptom Energy Metabolism Cardiology and Cardiovascular Medicine business Adenosine triphosphate Hydrogen |
| Zdroj: | The Journal of Thoracic and Cardiovascular Surgery. 114:601-608 |
| ISSN: | 0022-5223 |
| DOI: | 10.1016/s0022-5223(97)70050-3 |
| Popis: | Objectives: The pH of cardioplegic solutions is postulated to affect myocardial protection during neonatal hypothermic circulatory arrest. Neither optimization of cardioplegic pH nor its influence on intracellular pH during hypothermic circulatory arrest has been previously studied in vivo. Thus we examined the effects of the pH of cardioplegic solutions on postischemic cardiac function in vivo, including two possible operative mechanisms: (1) reduction in adenosine triphosphate use and depletion of high-energy phosphate stores or (2) reduction of H + flux during reperfusion, or both. Methods: Dynamic 31 P spectroscopy was used to measure rates of adenosine triphosphate use, high-energy phosphate depletion, cytosolic acidification during hypothermic circulatory arrest, and phosphocreatine repletion and realkalinization during reperfusion. Neonatal pigs in three groups (n = 8 each)—group A, acidic cardioplegia (pH = 6.8); group B, basic cardioplegia (pH = 7.8); and group N, no cardioplegia—underwent hypothermia at 20° C with 60 minutes of hypothermic cardioplegia followed by reperfusion. Results: Recoveries of peak elastance, stroke work, and diastolic stiffness were superior in group B. Indices of ischemic adenosine triphosphate use, initial phosphocreatine depletion rate, and τ, the exponential decay half-time, were not different among groups. Peak [H + ] in group A (end-ischemia) was significantly elevated over that of group B. The realkalinization rate was reduced in group B compared with that in groups A (p = 0.015) and N (p = 0.035), with no difference between groups A and N (p = 0.3). Cytosolic realkalinization rate was markedly reduced and the half-time of [H + ] decay was increased during reperfusion in group B. Conclusions: Superior postischemic cardiac function in group B is not related to alterations in ischemic adenosine triphosphate use or high-energy store depletion, but may be due to slowing in H + efflux during reperfusion, which should reduce Ca ++ and Na + influx. (J Thorac Cardiovasc Surg 1997;114:601-8) |
| Databáze: | OpenAIRE |
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