title: Desflurane-induced cardioprotection against ischemia-reperfusion injury depends on timing.
abstract: OBJECTIVE
  The authors tested the hypothesis that desflurane-induced cardioprotection depends on the timing of application and whether desflurane-induced postconditioning is mediated by nitric oxide.
  
  
  METHODS
  A prospective randomized vehicle-controlled study.
  
  
  METHODS
  A university research laboratory.
  
  
  METHODS
  New Zealand White rabbits (N = 56).
  
  
  METHODS
  Rabbits were instrumented and subjected to a 30-minute coronary artery occlusion (CAO) and 3 hours of reperfusion. Animals were randomized to 8 groups (n = 7) and received 0.0 or 1.0 minimum alveolar concentration desflurane for 30 minutes before CAO (PRE), during CAO (ISCH), after CAO (POST), before and after CAO (PRE + POST), or continuously for 90 minutes starting 30 minutes before CAO (PRE + ISCH + POST). In 2 separate experimental groups, the nitric oxide synthase inhibitor N-omega-nitro-L-arginine (L-NA) was administered before reperfusion in the presence or absence of desflurane. Data are mean +/- standard deviation.
  
  
  RESULTS
  Infarct size was 68% +/- 14% in control experiments. Desflurane significantly (p < 0.05) reduced infarct size in the PRE (43% +/- 9%) and POST groups (49% +/- 12%) but not in the ISCH group (69% +/- 9%). The PRE + ISCH + POST and PRE + POST groups produced similar reductions in infarct size to 47% +/- 12% and 43% +/- 9%, respectively. L-NA alone had no effect on infarct size (61% +/- 9%) but blocked postconditioning completely (L-NA + POST, 68% +/- 10%).
  
  
  CONCLUSIONS
  Desflurane induces pre- and postconditioning but does not confer cardioprotection during ischemia in rabbits. The combination of pre- and postconditioning or continuous application does not provide additional cardioprotection. Furthermore, desflurane-induced postconditioning is mediated by nitric oxide.
authors.affiliation: Department of Anesthesiology, University of Würzburg, Würzburg, Germany.
authors.forename: Thorsten M
authors.initials: TM
authors.lastname: Smul
authors.forename: Markus
authors.initials: M
authors.lastname: Lange
authors.forename: Andreas
authors.initials: A
authors.lastname: Redel
authors.forename: Jan
authors.initials: J
authors.lastname: Stumpner
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Lotz
authors.forename: Norbert
authors.initials: N
authors.lastname: Roewer
authors.forename: Franz
authors.initials: F
authors.lastname: Kehl
mesh_terms: D000818:Animals; D002316:Cardiotonic Agents / Q000627:therapeutic use*; D000077335:Desflurane; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods*; D007530:Isoflurane / Q000031:analogs & derivatives* / Q000627:therapeutic use; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000473:pathology / Q000517:prevention & control*; D018696:Neuroprotective Agents / Q000627:therapeutic use; D011817:Rabbits; D013997:Time Factors
chemical_list: D002316:Cardiotonic Agents; D018696:Neuroprotective Agents; D000077335:Desflurane; D007530:Isoflurane