Over the past decade hydrogen sulfide has emerged as an important cardioprotective molecule with potential for clinical applications. mammalian cells Salinomycin sodium salt providing neuromodulator functions was reported in 1996 (Abe 1996 Soon after the same group explained the part of H2S like Salinomycin sodium salt a mediator of vasorelaxation (Hosoki 1997 A steady interest for the part of H2S in physiology and disease has been mentioned since. H2S is definitely produced by three different enzymes namely cystathionine gamma-lyase (CSE) cystathionine beta-synthase (CBS) and 3-mercatopyruvate sulfurtransferase (3-MST) (Wang 2012) all of which are indicated in the heart (Kondo 2012). In spite of the lack of detailed studies within the relative level of manifestation of CBS CSE and 3MST in different vascular mattresses and in the myocardium it is claimed that CSE is the predominant source of enzymatically derived H2S in the cardiovascular system. In the heart this is true as H2S levels are reduced by 80% in CSE KO mice (King 2014). To deliver H2S to cells a number of donor compounds have been developed that differ in the mode and rate of H2S launch (Papapetropoulos 2015). Most studies have been performed using H2S salts (NaHS or Na2S) that are gradually being replaced by providers that more slowly launch H2S mimicking the endogenous generation of this gasotransmitter. H2S and cardioprotection Both endogenously produced and exogenously supplied H2S show cardioprotective actions [Andreadou 2015 Predmore 2011 Wang 2012 Szabo 2011 Polhemus 2014). While no studies on the part of CBS or 3MST in the heart have been published so far mice with targeted disruption of the CSE gene locus are more susceptible to myocardial damage after remaining coronary artery ligation (King 2014). In contrast mice over expressing CSE in their cardiomyocytes show greater degree of safety against ischemia-reperfusion injury (Elrod 2007). Pharmacological treatment with H2S donors in ischemia-reperfusion injury models applied either at the time of reperfusion or like a preconditioning agent preserves mitochondrial respiration attenuates the manifestation of inflammatory cytokines inhibits leukocyte recruitment reduces oxidative stress levels improves remaining ventricular function and reduces myocardial infarct size (Bian 2006; Bibli 2015; Calvert 2009 Calvert 2010; Elrod 2007 Sivarajah 2009 Sivarajah 2006 Improved myocardial survival and function has also been mentioned with H2S donors in heart failure and cardiomyopathy models (Wang 2012 Polhemus 2014). Even though part of H2S like a cardioprotective molecule is definitely well-established the signaling pathways mediating its effects are still under investigation. As attempts are under way to harness the restorative potential of H2S (Wallace and Wang 2015 the dosing plan (chronic vs acute H2S administration and timing of H2S software) as well as the choice of donors to be used for cardioprotection are important issues to consider if GPX1 drug development attempts are to come to fruition. Due to the importance of the NO/cGMP pathway in attenuating I/R injury (Andreadou 2015 Garcia-Dorado 2009) and based on the contribution of NO to the cardioprotective action of H2S (Bibli 2015 King 2014) herein we will focus on the connection between H2S cGMP and its target kinase cGMP-dependent protein kinase G in animal model of myocardial infarction. Interplay between NO and H2S Sufficient evidence for any cross-talk between H2S and the endothelial NO pathway is present with most of Salinomycin sodium salt the evidence pointing towards a synergistic action of the two gasotransmitters. H2S enhances Akt activity (Papapetropoulos 2009) probably through PTEN inhibition (Greiner 2014) triggering eNOS phosphorylation on Ser1177 and improved NO production (Coletta 2012 King 2014). At the same time H2S serves as a potent and selective PDE5 inhibitor exhibiting a 30-collapse selectivity for PDE5 over additional PDEs (Bucci 2010 Panopoulos 2015). Moreover H2S also prevents nitrosation of eNOS on Cys443 keeping it in the active dimeric form (Altaany 2014). H2S also retains the soluble guanylyl cyclase the NO “receptor” in its ferrous NO-responsive form (Zhou 2015). In the practical level it has been demonstrated the actions of H2S and NO are mutually dependent in the vessel wall as inhibition of the production of one gasotransmitter abolishes or reduces angiogenesis and vascular relaxation triggered from the additional (Coletta 2012). The connection between H2S and Salinomycin sodium salt NO has been confirmed to occur in the heart where H2S donor administration resulted in increased eNOS.