title: Hydrogen sulfide contributes to cardioprotection during ischemia-reperfusion injury by opening K ATP channels.
abstract: The present study was undertaken to investigate the protective effect of H2S against myocardial ischemia-reperfusion (I/R) injury and its possible mechanism by using isolated heart perfusion and patch clamp recordings. Rat isolated hearts were Langendorff-perfused and subjected to a 30-minute ischemia insult followed by a 30-minute reperfusion. The heart function was assessed by measuring the LVDP, +/-dP/dt max, and the arrhythmia score. The results showed that the treatment of hearts with a H2S donor (40 micromol/L NaHS) during reperfusion resulted in significant improvement in heart function compared with the I/R group (LVDP recovered to 85.0% +/- 6.4% vs. 35.0% +/- 6.1%, +dP/dt max recovered to 80.9% +/- 4.2% vs. 43.0% +/- 6.4%, and -dP/dt max recovered to 87.4% +/- 7.3% vs. 53.8% +/- 4.9%; p < 0.01). The arrhythmia scores also improved in the NaHS group compared with the I/R group (1.5 +/- 0.2 vs. 4.0 +/- 0.4, respectively; p < 0.001). The cardioprotective effect of NaHS during reperfusion could be blocked by an ATP-sensitive potassium channel (K ATP) blocker (10 micromol/L glibenclamide). In single cardiac myocytes, NaHS increased the open probability of K ATP channels from 0.07 +/- 0.03 to 0.15 +/- 0.08 after application of 40 mumol/L NaHS and from 0.07 +/- 0.03 to 0.36 +/- 0.15 after application of 100 mumol/L NaHS. These findings provide the first evidence that H2S increases the open probability of K ATP in cardiac myocytes, which may be responsible for cardioprotection against I/R injury during reperfusion.
authors: Department of Physiology, School of Basic Medical Sciences, Capital Medical University, Beijing, PR China.
authors: Zhifei
authors: Z
authors: Zhang
authors: Haixia
authors: H
authors: Huang
authors: Ping
authors: P
authors: Liu
authors: Chaoshu
authors: C
authors: Tang
authors: Jun
authors: J
authors: Wang
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000503:physiopathology / Q000517:prevention & control; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D005905:Glyburide / Q000494:pharmacology; D006321:Heart / Q000503:physiopathology; D006862:Hydrogen Sulfide / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000502:physiology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000503:physiopathology / Q000517:prevention & control*; D013440:Sulfides / Q000494:pharmacology
chemical_list: D002316:Cardiotonic Agents; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D013440:Sulfides; C025451:sodium bisulfide; D005905:Glyburide; D006862:Hydrogen Sulfide