4.1 Sulfates
Sulfalts are currently the most common hydrogen sulfide donors in biological research, such as sodium sulfide and sodium hydrosulfide, which have been shown to have protective effects on cells in disease states in multiple studies[44]. Both sodium sulfide and sodium hydrosulfide exhibit crystalline powder appearance, which is easily soluble in water and can provide hydrogen sulfide more directly. In early studies, Wang et al. used NaHS aqueous solution to release H2S and found that it can reduce systemic arterial pressure, indicating that hydrogen sulfide has the characteristic of relaxing blood vessels[45]. This has been verified in the research of Daniel et al., in addition, they also found that the reduction of hydrogen sulfide donors will lead to the reduction of cardiac output, which will lead to the reduction of systemic arterial pressure, and this phenomenon does not depend on the regulation of the central nervous system[46]. In multiple studies, hydrogen sulfide released by exogenous donor NaHS can play a protective role in organ damage, such as myocardial damage[47, 48],liver[49],brain[50],kidney[48]et. However, the chemical properties of sulfide salts are not stable, and the dosage and speed of hydrogen sulfide produced after direct dissolution in water are uncontrollable. The release of a large amount of hydrogen sulfide can cause a sudden drop in blood pressure, which has adverse effects on experimental animals.