title: Effect of hydrogen sulfide in a porcine model of myocardial ischemia-reperfusion: comparison of different administration regimens and characterization of the cellular mechanisms of protection.
abstract: OBJECTIVE
  We investigate the impact of different regimens of parenteral hydrogen sulfide (H2S) administration on myocardium during ischemia-reperfusion (IR) and the molecular pathways involved in its cytoprotective effects.
  
  
  METHODS
  Eighteen male Yorkshire pigs underwent 60 minutes of mid-left anterior descending coronary artery occlusion followed by 120 minutes of reperfusion. Pigs received either placebo (control, n = 6) or H2S as a bolus (bolus group, n = 6, 0.2 mg/kg over 10 seconds at the start of reperfusion) or as an infusion (infusion group, n = 6, 2 mg.kg.h initiated at the onset of ischemia and continued into the reperfusion period). Myocardial function was monitored throughout the experiment. The area at risk and myocardial necrosis was determined by Monastral blue/triphenyl tetrazolium chloride staining. Apoptosis and the expression pattern of various intracellular effector pathways were investigated in the ischemic territory. Coronary microvascular reactivity to endothelium-dependent and endothelium-independent factors was measured.
  
  
  RESULTS
  H2S infusion but not bolus administration markedly reduce myocardial infarct size (P < 0.05) and improve regional left ventricular function, as well as endothelium-dependent and endothelium-independent microvascular reactivity (P < 0.05). The expression of B-cell lymphoma 2 (P = 0.059), heat shock protein 27 and alphaB-crystallin (P < 0.05) were lower in H2S-treated groups. Infusion of H2S caused higher expression of phospho-glycogen synthase kinase-3 beta isoform(P < 0.05) and lower expression of mammalian target of rapamycin and apoptosis-inducing factor (P < 0.05). Bolus of H2S caused higher expression of phospho-p44/42 MAPK extracellular signal-regulated kinase and lower expression of Beclin-1 (P < 0.05). The expression of caspase 3 and cleaved caspase 3 were lower (P < 0.05), whereas the expression of phospho-Bad(Ser136) was higher in the bolus group versus control and infusion groups (P < 0.05). The terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cell count was lower in both H2S-treated groups compared with the control (P < 0.05).
  
  
  CONCLUSIONS
  This study demonstrates that infusion of H2S is superior to a bolus alone in reducing myocardial necrosis after IR injury, even though some markers of apoptosis and autophagy were affected in both H2S-treated groups. Thus, the current results indicate that infusion of H2S throughout IR may offer better myocardial protection from IR injury.
authors.affiliation: Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Osipov
authors.forename: Michael P
authors.initials: MP
authors.lastname: Robich
authors.forename: Jun
authors.initials: J
authors.lastname: Feng
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Liu
authors.forename: Richard T
authors.initials: RT
authors.lastname: Clements
authors.forename: Hilary P
authors.initials: HP
authors.lastname: Glazer
authors.forename: Neel R
authors.initials: NR
authors.lastname: Sodha
authors.forename: Csaba
authors.initials: C
authors.lastname: Szabo
authors.forename: Cesario
authors.initials: C
authors.lastname: Bianchi
authors.forename: Frank W
authors.initials: FW
authors.lastname: Sellke
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002316:Cardiotonic Agents / Q000008:administration & dosage* / Q000097:blood / Q000627:therapeutic use*; D002470:Cell Survival / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D004195:Disease Models, Animal; D006862:Hydrogen Sulfide / Q000008:administration & dosage* / Q000097:blood / Q000627:therapeutic use*; D020287:In Situ Nick-End Labeling; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D009203:Myocardial Infarction / Q000209:etiology / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D015428:Myocardial Reperfusion Injury / Q000150:complications / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology; D013552:Swine; D019210:Troponin I / Q000097:blood; D016277:Ventricular Function, Left / Q000187:drug effects
chemical_list: D002316:Cardiotonic Agents; D019210:Troponin I; D006862:Hydrogen Sulfide