The low rate of release of H2S species from GYY4137 is reflected by the different sensitivity of these relaxations towards high K+ concentration and potassium channel blockers compared with Na2S. The perspective is that the rate of release of sulfides plays an important for the effects of H2S salt vs. donors in small arteries, and hence for a beneficial effect of GYY4137 for treatment of cardiovascular disease. Here, KCNA3 is linked to cardiovascular disorder.