Abstract: Abstract: Objective To investigate the protective effect of hydrogen sulfide delayed preconditioning with mitochondrial ATP sensitive potassium channel[mitoK(ATP)] activation on rat myocardial cells. Methods Thirty-two S-D adult male rats were randomly divided into a Sham group, an IR group, a HS group and a HD group(n = 8). In Sham group, we isolated left anterior descending(LAD) coronary artery, but not blocked for 150 minutes; in IR group, we blocked LAD for 30 min and then primed for 2h; in HS group, we injected donor of hydrogen sulfide — sodium hydrosulfide 50μg/kg via vein, after 24h, dealed the same with IR group; in HD group, we injected 5-HD 15min before blocking LAD via vein, others dealed the same with HS group. the myocardial infarct size and area at risk were determined; the myocardial ultrastructure was observed by electron microscope. Results Compared with IR group, the infarct size was reduced and the damage of myocardial ultrastructure was depressed in HS group(P<0.05). Compared with IR group, there was no significant difference in HA group(P>0.05). Conclusion Hydrogen sulfide delayed preconditioning can protect the cardiomyocytes by activating the KATP channel.

Key words: hydrogen sulfide, preconditioning, ischemia reperfusion, potassium channel