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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Animals, Celecoxib, Cyclooxygenase 2, Cyclooxygenase 2 Inhibitors, Erythropoietin, Ischemic Preconditioning, Myocardial, Ligation, Male, Myocardial Ischemia, Myocardial Reperfusion Injury, Pyrazoles, Rats, Rats, Sprague-Dawley, Recombinant Proteins, Sulfonamides.
user
Does cyclooxygenase-2 play an essential part in cardioprotection of delayed phase of recombinant human erythropoietin preconditioning in rats? Context: To study the cardioprotection of recombinant human erythropoietin (rhEPO) preconditioning (EPC) and to investigate the role and possible mechanism of cyclooxygenase (COX)-2 in the delayed phase of EPC. In phase 1, myocardial ischaemia reperfusion (I-R) rat model was established by 30 minutes ligation of left descending coronary and three hours of reperfusion. Rats were given 0.9% saline solution or rhEPO 24 hours before I-R protocol. COX-2 selective inhibitor celecoxib was given for further investigation of the cardioprotection of EPC. At the end of I-R protocol, infarct sizes were measured and ultrastructural organisations were studied. In phase 2, myocardial COX-2 mRNA expressions and prostaglandins (PGs) contents were studied in different groups after euthanasia. It was found that EPC could elicit potent cardioprotection against I-R injury, shown by reduction of infarct size and improvement of ultrastructural organisation; whereas administration of celecoxib resulted in complete loss of this protection. EPC resulted in robust increase in COX-2 mRNA and PGs levels that were also abrogated by celecoxib.
assistant
COX-2 plays an essential part in cardioprotection of the delayed phase of EPC in rats, which might be related to actions of PGE(2) or PGI(2), or both. Final Decision: yes