An Integrated View of the Chemical Biology of NO, CO, H2S, and O2

Abstract It is clear that the small molecule signals/bioregulators NO, CO, H 2 S, and O 2 all possess unique and important physiological functions. However, it is becoming increasingly evident that these species can interact with each other, control each other’s biosynthesis, and/or compete at biological targets. Thus, the biological actions of one species can be altered by the presence of another. For these reasons, a complete understanding of the physiology of one small molecule bioregulator requires an integrated view that considers the others (as well as derived species). Herein, a brief discussion of the chemistry and biology of NO, CO, H 2 S, and O 2 is given with an emphasis on the potential interaction between them.