[COX-2 mediates U50488H-induced delayed cardioprotection in isolated rat heart].

Abstract

OBJECTIVE:

To determine whether U50488H, a selective agonist of kappa-opioid receptor, could induce biphasic (early and late) cardioprotection against myocardial ischemia/reperfusion injury and to explore the underlying mechanisms.

METHODS:

Isolated perfused rat hearts were subjected to 30 min of ischemia followed by 120 min reperfusion and the cardiac function was evaluated.

RESULT:

Left ventricular end-diastolic pressure (LVEDP), left ventricular developed pressure (LVDP) and maximal velocity of contraction and relaxation (+/-dP/dtmax) were improved when U50488H was administered 1 or 24 h before ischemia (P<0.05). Myocardial infarct size, activities of creatine kinase (CK) and lactate dehydrogenase (LDH) in the coronary effluent were lower in the U50488H pretreatment group than those in the control group. Administration of a selective cyclooxygenase-2 (COX-2) inhibitor, celecoxib abolished the late phase of cardioprotection produced by administration of U50488H 24 h before ischemia. Activities of CK and LDH in the coronary effluent were higher in U50488H and celecoxib co-pretreatment group than those in U50488H group. However, administration of celecoxib did not block the early phase of cardioprotection by 1 h treatment of U50488H before ischemia.

CONCLUSION:

The late (but not the early) phase of cardioprotection induced by kappa-opioid receptor agonist might be mediated by COX-2.

• Authors: Bi-e Tang, Ying-ying Chen, Wei Guo, Di-sen Mei, Qing Xu, Ye Hu, Yue-liang Shen, Qiang Xia
• Journal: Zhejiang da xue xue bao. Yi xue ban = Journal of Zhejiang University. Medical sciences (Zhejiang Da Xue Xue Bao Yi Xue Ban) Vol. 35 Issue 2 Pg. 165-71 (03 2006) ISSN: 1008-9292 [Print] China
• PMID: 16610083 (Publication Type: English Abstract, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cardiotonic Agents
• Receptors, Opioid, kappa
• 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer
• L-Lactate Dehydrogenase
• Cyclooxygenase 2
• Creatine Kinase

Topics

• 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer (pharmacology)
• Animals
• Cardiotonic Agents (pharmacology)
• Creatine Kinase (metabolism)
• Cyclooxygenase 2 (physiology)
• In Vitro Techniques
• Ischemic Preconditioning, Myocardial
• L-Lactate Dehydrogenase (metabolism)
• Male
• Myocardial Infarction (enzymology, pathology)
• Myocardial Reperfusion Injury (prevention & control)
• Rats
• Rats, Sprague-Dawley
• Receptors, Opioid, kappa (agonists)