BackgroundEctonucleotidase plays an important role in the regulation of cardiac function by controlling extracellular levels of adenine nucleotides and adenosine. To determine the influence of ischemia-reperfusion injury on ectonucleotidase activity in coronary vascular bed, we compared the metabolic profile of adenine nucleotides during the coronary circulation in pre- and post-ischemic heart.MethodsLangendorff-perfused rat hearts were used to assess the intracoronary metabolism of adenine nucleotides. The effects of ischemia on the adenine nucleotide metabolism were examined after 30 min of ischemia and 30 min of reperfusion. Adenine nucleotide metabolites were measured by high performance liquid chromatography.ResultsATP, ADP and AMP were rapidly metabolized to adenosine and inosine during the coronary circulation. After ischemia, ectonucleotidase activity of the coronary vascular bed was significantly decreased. In addition, the perfusate from the ischemic heart contained a considerable amount of enzymes degrading ATP, AMP and adenosine. Immunoblot analysis revealed that the perfusate from the ischemic heart dominantly contained ectonucleoside triphosphate diphosphohydrolase 1, and, to a lesser extent, ecto-5’-nucleotidase. The leakage of nucleotide metabolizing enzymes from the coronary vascular bed by ischemia-reperfusion was more remarkable in aged rats, in which post-ischemic cardiac dysfunction was more serious.ConclusionEctonucleotidases were liberated from the coronary vascular bed by ischemia-reperfusion, resulting in an overall decrease in ectonucleotidase activity in the post-ischemic coronary vascular bed. These results suggest that decreased ectonucleotidase activity by ischemia may exacerbate subsequent reperfusion injury, and that levels of circulating ectonucleotidase may reflect the severity of ischemic vascular injury.

: Two patients who underwent thoracic epidural neurolysis after titration using local anesthetic are reported. Case 1 suffered serious back and epigastric pain arising from metastasis of lung cancer and Case 2 was not relieved right chest pain by costal metastasis from urethral cancer only by morphine. Block therapies improve the patients' quality of life if these underwent in opioid resistant pain or moving pain. Among them subarachnoid neurolytic blockage or epidural continuous blockage are usually selected in terminal stage. Subarachnoid blockage is potent but usually induces paresthesia and hypesthesia and patient has to keep lateral position under affected site intraoperatively. Epidural block is easy to treat but is difficult to continue because of infection and decrement of efficacy attributed adhesion of epidural space, stress arose from immobilization. We operate epidural neurolytic blockage for these patients and they were relieves from pain without suffer from the side effect.