title: Confined ischemia may improve remote myocardial outcome after rat cardiac arrest.
abstract: BACKGROUND
  Confined ongoing ischemia after ischemia-reperfusion injury (IRI) may alter myocardial recovery. We evaluated in a rat cardiac transplantation model whether distal persistent myocardial ischemia (dMI) and remote preconditioning (RPreC) have a remote myocardial impact after IRI.
  
  
  METHODS
  Syngeneic heterotopic cardiac transplantation was performed on 29 Fischer344 rats to induce IRI, including nine rats which underwent distal ligation of the left anterior coronary artery (LAD) to yield distal MI (IRI+ dMI). RPreC was applied by occluding the left renal artery 5 min prior to reperfusion in six rats with IRI (IRI+ RPreC) as well as in seven with distal MI (IRI+ dMI+ RPreC). Microdialysis, histology and qRT-PCR for inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) were performed after graft harvesting.
  
  
  RESULTS
  In contrast to IRI + dMI + RPreC (39 ± 7 μmol), glutamate decreased in IRI + RPreC and IRI + dMI as compared with IRI (26 ± 3 and 31 ± 8 vs 91 ± 20, μmol respectively, p < 0.007). The relative number of vacuolated intramyocardial artery nuclei decreased in IRI + dMI as compared with IRI (0.02 ± 0.01, range 0-12 vs. 0.42 ± 0.31, range 0-3.25 PSU respectively, p < 0.04). iNOS expression decreased in IRI + RPreC as compared with IRI (p < 0.04), and eNOS expression decreased in IRI + dMI + RPreC as compared with IRI + dMI (p < 0.006) along with increased glycerol release.
  
  
  CONCLUSIONS
  dMI after IRI has a potentially beneficial myocardial impact after cardiac arrest, which is hampered by RPreC.
authors.affiliation: Heart Center, Cardiac Research, Tampere University Hospital and Tampere University , Tampere , Finland.
authors.forename: Zanxin
authors.initials: Z
authors.lastname: Wang
authors.forename: Hongyan
authors.initials: H
authors.lastname: Li
authors.forename: Vilma
authors.initials: V
authors.lastname: Vuohelainen
authors.forename: Jyrki
authors.initials: J
authors.lastname: Tenhunen
authors.forename: Mari
authors.initials: M
authors.lastname: Hämäläinen
authors.forename: Timo
authors.initials: T
authors.lastname: Rinne
authors.forename: Eeva
authors.initials: E
authors.lastname: Moilanen
authors.forename: Timo
authors.initials: T
authors.lastname: Paavonen
authors.forename: Matti
authors.initials: M
authors.lastname: Tarkka
authors.forename: Ari
authors.initials: A
authors.lastname: Mennander
mesh_terms: D000818:Animals; D003331:Coronary Vessels / Q000201:enzymology / Q000473:pathology; D015870:Gene Expression; D018698:Glutamic Acid / Q000378:metabolism; D006323:Heart Arrest / Q000201:enzymology / Q000601:surgery*; D016027:Heart Transplantation; D019157:Ischemic Preconditioning, Myocardial; D015428:Myocardial Reperfusion Injury / Q000201:enzymology / Q000517:prevention & control*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D018698:Glutamic Acid; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496318:Nos2 protein, rat; C496316:Nos3 protein, rat