title: Role of atrial natriuretic Peptide in oxytocin induced cardioprotection.
abstract: BACKGROUND
  The purpose of this study was to determine whether endogenous atrial natriuretic peptide (ANP) contributes to the protective effect of neurohypophysial hormone oxytocin (OT) in heart preconditioning.
  
  
  METHODS
  Sprague-Dawley male rats were subjected to 25 min regional ischaemia and 120 min reperfusion and were divided into eight groups. Oxytocin or an equivalent volume of saline was administrated intraperitoneally, 30 min before ischaemia. The OT receptor antagonist (atosiban), ANP receptor antagonist (anantin) and nitric oxide synthase inhibitor (L-NAME) were injected 10 min before OT. In other groups, atosiban, anantin and L-NAME were only administered 40 min prior to ischaemia.
  
  
  RESULTS
  Compared with the ischaemia/reperfusion group (I/R), alterations in infarct size, biochemical parameters [LDH (lactate dehydrogenase), CK-MB (creatine kinase-MB), MDA (malondialdehyde) plasma levels] and severity of ventricular arrhythmia due to I/R injury were attenuated and VF was abolished by OT treatment. These OT effects were eliminated by OT and ANP receptor blockers and nitric oxide synthase inhibitor, but anantin did not reverse the effect of OT in lipid peroxidation.
  
  
  CONCLUSIONS
  These findings demonstrate an important contributory role of ANP in the OT induced protection in myocardial ischaemia reperfusion. OT also reduced lipid peroxidation with a NO-dependent mechanism.
authors.affiliation: Department of Physiology, School of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Islamic Republic of Iran.
authors.forename: Fariba
authors.initials: F
authors.lastname: Houshmand
authors.affiliation: Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran. Electronic address: faghihim@tums.ac.ir.
authors.forename: Mahdieh
authors.initials: M
authors.lastname: Faghihi
authors.affiliation: Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran.
authors.forename: Saleh
authors.initials: S
authors.lastname: Zahediasl
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D002316:Cardiotonic Agents / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006727:Hormone Antagonists / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D009203:Myocardial Infarction / Q000378:metabolism / Q000517:prevention & control*; D015428:Myocardial Reperfusion Injury / Q000378:metabolism / Q000517:prevention & control*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D010120:Oxytocics / Q000494:pharmacology; D010121:Oxytocin / Q000494:pharmacology*; D010456:Peptides, Cyclic / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014668:Vasotocin / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D002316:Cardiotonic Agents; D004791:Enzyme Inhibitors; D006727:Hormone Antagonists; D010120:Oxytocics; D010456:Peptides, Cyclic; C047046:atosiban; C068090:anantin; D010121:Oxytocin; D009320:Atrial Natriuretic Factor; D019331:NG-Nitroarginine Methyl Ester; D014668:Vasotocin
keywords: Atrial natriuretic peptide; Ischaemia reperfusion; Oxidative stress; Oxytocin; Preconditioning.