Hydrogen Sulfide Induced Delayed Cardioprotection And Its Mechanisms In Rats

Part one The protection of hydrogen sulfide delayed preconditioning in rat myocardium after ischemic reperfusion.Objective:To investigate the protection of hydrogen sulfide delayed preconditioning on myocardial ischemia reperfusion injury in the rats.Methods:Four groups (n= 10 animals/group) of Sprague-Dawley male rats were studied:group S, control rats that received no treatment; group IR, rats treated with NS (1.0 ml/kg iv) 24 h before ischemia; group H, rats treated with NaHS (0.05 mg/kg iv) 24 h before ischemia; and groups D, NaHS-treated animals that received the 5-hydroxydecanoate (5-HD), an inhibitor of mitochondrial KATP channels 15 min before ischemia. Group IR, H and D were subjected to ischemia by 30 min of coronary artery occlusion followed by 2 h of reperfusion. At the end of the reperfusion, myocardial infarct size, the activity of superoxide dismutase(SOD) and the content of malondialdehyde (MDA) in blood were measured. The myocardial ultrastructures were observed under the electron microscopy.Results:NaHS caused a significant reduction in infarct size [25.40 +/-3.54 vs.38.27+/-5.64%(%area at risk) in controls, P< 0.05] that was blocked by 5-HD (40.53+/-5.24%, P< 0.05).5-HD did not change infarct size vs control rats. Group H had a lower level of MDA and a higher level of SOD than that of group IR. The activity of SOD and the level of MDA in group D were as the same change as that of group IR(P>0.05). The degree injury of Group H was change better than that of Group IR under the electron microscope, but no change in group D.Conclusion:Hydrogen sulfide preconditioning induces the late cardioprotection against ischemia reperfusion injury in the rats, and mediated by opening of KATP channel. Part two proteomics analysis of hydrogen sulfide delayed preconditioning on rat myocardiumObjective:To investigate the changes of myocardial protein expression 24 h after hydrogen sulfide pretreatment, and to search for the mechanism porbably involved in the delayed precondtioning of hydrogen sulfide with proteomics techniques.Methods:Proteomics analysis of myocardium of hydrogen sulfide pretreatment. The left ventricle tissues of hydrogen sulfide(group H) or NS(group S) preconditioned rats were sampled for proteomics analysis.The total proteins were extracted and separated by two dimensional gel elecrtophoresis(2-DE), and 15 differential expression protein spots were analyzed with martix-assisted laser desorption/ ionization time-of-flihgt mass spectrometry(MALDI-TOF-MS).Results:Analysis of 2-DE showed that 929±14 portein spots were in group S and 906±10 protein spots in group H, and that the expression of 15 protein spots were different between the two groups.15 portein spots were choosed for MS analysis, and 11 porteins were preliminarily identified. These proteins can be classified into four functional groups: metabolism related proteins(Fructose-bisphosphate aldolase A), anti-oxidant related proteins(Glutathione S-transferase, S-adenosylmethionine synthetase), respiratory chain related proteins(Electron transfer flavoprotein subunit beta, NADH dehydrogenase) and cell protection related proteins(Glycogen synthase kinase-3, Cystathionine gamma-lyase).Conclusions:Hydrogen sulfide delayed preconditioning resulted in the changes of protein expression profiles in the myocardium.The differential proteins might function as anti-oxidant reaction and improve the energy metabolism of myocardium to confer cardioprotection. Part three Effect of hydrogen sulfide induced delayed preconditioning on glutathione S-transferase(GST) expression during myocardial ischemia-reperfusion in ratsObjective:To investigate the effect of hydrogen sulfide induced delayed preconditioning on glutathione S-transferase(GST) expression during myocardial ischemia-reperfusion in rats.Methods:Four groups (n= 10 animals/group) of Sprague-Dawley male rats were studied:group S, control rats that received no treatment; group IR, rats treated with NS (1.0 ml/kg iv) 24 h before ischemia; group H, rats treated with NaHS (0.05 mg/kg iv) 24 h before ischemia; and groups D, NaHS-treated animals that received the 5-hydroxydecanoate (5-HD), an inhibitor of mitochondrial KATP channels 15 min before ischemia. Group IR, H and D were subjected to ischemia by 30 min of coronary artery occlusion followed by 2 h of reperfusion. At the end of the reperfusion, myocardial infarct size was measured. Glutathione S-transferase(GST) was measured by Western blotting.Results:NaHS caused a significant reduction in infarct size [25.40 +/-3.54 vs.38.27+/-5.64%(%area at risk) in controls, P< 0.05] that was blocked by 5-HD (40.53+/-5.24%, P< 0.05).5-HD did not change infarct size vs control rats. Group H had a lower level of MDA and a higher level of SOD than that of group IR. Hydrogen sulfide treatment induced the higher expression of GST in hearts, but 5-HD abolished the effect.Conclusion:The hydrogen sulfide induced delayed preconditioning attenuates myocardial I/R injury possibly through up-regulating glutathione S-transferase expression in rats.