Abstract 16381: Novel Thiol-activated H2S Donors Attenuate Myocardial Ischemia/Reperfusion Injury

Abstract

Background: Hydrogen sulfide (H2S) protects against acute myocardial ischemia/reperfusion (MI/R) injury and heart failure by ameliorating oxidative stress, improving mitochondrial function, and attenuating apoptosis. One of the major limitations of currently available H2S donors is poor pharmacokinetics profiles that result in very rapid and uncontrolled H2S release. NSHD-1 and NSHD-2 are recently developed thiol-activated H2S donors designed for sustained release of H2S upon activation by molecules containing thiol groups such as cysteine and glutathione. We hypothesized that these novel H2S donors would generate H2S for extended periods and ameliorate myocardial cell death following MI/R in an in vivo murine model. Methods and Results: C57BL6/J male mice (10-12 weeks of age) were subjected to 45 minutes of MI followed by 24 hours of R. At the time of reperfusion, animals received Vehicle (0.5% THF), NSHD-1 (50 μg/kg and 100 μg/kg), or NSHD-2 (50 μg/kg) by direct intracardiac (i.c.) injection. In addition, at 4 hours of R, plasma was collected for troponin-I measurements. In preliminary studies we observed sustained release of H2S with both of these H2S donors. Myocardial infarct size was reduced by 35% (p < 0.01 vs. Vehicle) in mice treated with NSHD-1 (100 μg/kg), 43% (p < 0.05 vs. Vehicle) in mice treated with NSHD-2 (50 μg/kg), and 54% (p < 0.01 vs. Vehicle) in mice treated with NSHD-2 (100 μg/kg). Conclusions: NSHD-1 and NSHD-2 significantly attenuate MI/R injury in a murine model. Experiments are currently underway to further define the in vivo pharmacokinetics of H2S release from these agents, mechanisms of action, and safety profile.