title: Remifentanil postconditioning has cross talk with adenosine receptors in the ischemic-reperfused rat heart.
abstract: BACKGROUND
  Although there is a possibility of cross talk between opioid and adenosine signaling pathways in the ischemic-reperfused myocardium, it is not clear that an ultra-short-acting opioid receptor agonist remifentanil-induced postconditioning (RPostC) has cross talk with adenosine receptor (ADR). The purpose of this study was to determine whether there is cross talk with ADR in RPostC.
  
  
  METHODS
  Isolated rat hearts were subjected to 30 min of regional ischemia and 2 h of reperfusion. RPostC was induced by 100 ng/mL of remifentanil perfusion, 5 min before reperfusion, followed by 5 min of reperfusion. The nonspecific opioid receptor antagonist naloxone (NAL) and the nonspecific ADR antagonist 8-(p-sulfophenyl) theophylline hydrate (8-SPT) were perfused for a 20-min period, 10 min before RPostC to the end of RPostC. Western blot analysis was performed to detect phospho-ERK1/2 in cultured cardiomyocytes.
  
  
  RESULTS
  In cultured cardiomyocytes, remifentanil incubation significantly increased the phosphorylation of ERK1/2 and this effect was blocked by both NAL and 8-SPT (P < 0.01 and P < 0.05, respectively). RPostC significantly reduced infarct size over ischemic area at risk from 34.1 ± 10.5% to 16.6 ± 7.5% (P < 0.05 versus control). The infarct-limitation effect of RPostC was reversed by both NAL (33.8 ± 13.0%, P < 0.05) and 8-SPT (35.7 ± 14.5%, P < 0.01).
  
  
  CONCLUSIONS
  This study strongly implies that the intracellular signaling pathways of cardioprotection by RPostC has cross talk with ADR in the ischemic-reperfused myocardium.
authors: Department of Anesthesiology and Pain Medicine, Graduate School, Keimyung University, Daegu, Korea.
authors: Jeon-Yu
authors: JY
authors: Ha
authors: Department of Anesthesiology and Pain Medicine, Keimyung University School of Medicine, Daegu, Korea. Electronic address: yclee@dsmc.or.kr.
authors: Yong-Cheol
authors: YC
authors: Lee
authors: Department of Anesthesiology and Pain Medicine, Yeungnam University College of Medicine, Daegu, Korea.
authors: Sang-Jin
authors: SJ
authors: Park
authors: Institute of Cardiovascular Research, Pusan National University Yangsan Hospital, Yangsan-si, Gyeongsangnam-do, Korea.
authors: Young-Ho
authors: YH
authors: Jang
authors: Institute of Cardiovascular Research, Pusan National University Yangsan Hospital, Yangsan-si, Gyeongsangnam-do, Korea.
authors: June-Hong
authors: JH
authors: Kim
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D001699:Biometry; D015153:Blotting, Western; D002478:Cells, Cultured; D003326:Coronary Circulation; D006334:Heart Function Tests; D066298:In Vitro Techniques; D057775:Ischemic Postconditioning; D008297:Male; D009203:Myocardial Infarction / Q000473:pathology; D009206:Myocardium / Q000473:pathology; D010880:Piperidines / Q000494:pharmacology*; D058906:Purinergic P1 Receptor Agonists / Q000494:pharmacology; D011897:Random Allocation; D017207:Rats, Sprague-Dawley; D020239:Receptor Cross-Talk; D018047:Receptors, Purinergic P1 / Q000187:drug effects*; D000077208:Remifentanil; D015427:Reperfusion Injury / Q000473:pathology
chemical_list: D000701:Analgesics, Opioid; D010880:Piperidines; D058906:Purinergic P1 Receptor Agonists; D018047:Receptors, Purinergic P1; D000077208:Remifentanil
keywords: Adenosine receptor; Cross talk; Opioid receptor; Postconditioning; Remifentanil