title: The production of hydrogen sulfide limits myocardial ischemia and reperfusion injury and contributes to the cardioprotective effects of preconditioning with endotoxin, but not ischemia in the rat.
abstract: We investigated whether (endogenous) hydrogen sulfide (H2S) protects the heart against myocardial ischemia and reperfusion injury. Furthermore, we investigated whether endogenous H2S is involved in the protection afforded by (1) ischemic preconditioning and (2) the second window of protection caused by endotoxin. The involvement of one of the potential (end) effectors of the cardioprotection afforded by H2S was investigated using the mitochondrial KATP channel blocker, 5-hydroxydecanoate (5-HD; 5 mg/kg). Animals were subjected to 25 min regional myocardial ischemia followed by reperfusion (2 h) and were pretreated with the H2S donor, sodium hydrosulfide (3 mg/kg i.v.). Animals were also subjected to shorter periods of myocardial ischemia (15 min) and reperfusion (2 h) and pretreated with an irreversible inhibitor of cystathionine-gamma-lyase, dl-propargylglycine (PAG; 50 mg/kg i.v.). Animals were also pretreated with PAG (50 mg/kg) and subjected to either (1) ischemic preconditioning or (2) endotoxin (1 mg/kg i.p.) 16 h before myocardial ischemia. Myocardial infarct size was determined by p-nitroblue tetrazolium staining. Administration of sodium hydrosulfide significantly reduced myocardial infarct size, and this effect was abolished by 5-HD. Administration of PAG (50 mg/kg) or 5-HD significantly increased infarct size caused by 15 min of myocardial ischemia. The delayed cardioprotection afforded by endotoxin was abolished by 5-HD or PAG. In contrast, PAG (50 mg/kg) did not affect the cardioprotective effects of ischemic preconditioning. These findings suggest that (1) endogenous H2S is produced by myocardial ischemia in sufficient amounts to limit myocardial injury and (2) the synthesis or formation of H2S by cystathionine-gamma-lyase may contribute to the second window of protection caused by endotoxin.
authors.affiliation: Centre for Experimental Medicine, Nephrology & Critical Care, The William Harvey Research Institute, St. Bartholomew's and The Royal London School of Medicine and Dentistry, Queen Mary-University of London, Charterhouse Square, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Sivarajah
authors.forename: M C
authors.initials: MC
authors.lastname: McDonald
authors.forename: C
authors.initials: C
authors.lastname: Thiemermann
mesh_terms: D000480:Alkynes / Q000494:pharmacology; D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D003542:Cystathionine gamma-Lyase / Q000037:antagonists & inhibitors; D003652:Decanoic Acids / Q000494:pharmacology; D004731:Endotoxins / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D006862:Hydrogen Sulfide / Q000378:metabolism*; D006880:Hydroxy Acids / Q000494:pharmacology; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods*; D008297:Male; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009203:Myocardial Infarction / Q000188:drug therapy / Q000473:pathology; D017202:Myocardial Ischemia / Q000378:metabolism / Q000517:prevention & control*; D015428:Myocardial Reperfusion Injury / Q000378:metabolism / Q000517:prevention & control*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013440:Sulfides / Q000494:pharmacology
chemical_list: D000480:Alkynes; D002316:Cardiotonic Agents; D003652:Decanoic Acids; D004731:Endotoxins; D004791:Enzyme Inhibitors; D006880:Hydroxy Acids; D026902:Potassium Channel Blockers; D013440:Sulfides; C052853:5-hydroxydecanoic acid; C009055:propargylglycine; D003542:Cystathionine gamma-Lyase; C025451:sodium bisulfide; D005998:Glycine; D006862:Hydrogen Sulfide