Ancient origins of nitric oxide signaling in biological systems.

Abstract

The simple gas nitric oxide (NO) controls a variety of complex biological processes, including blood pressure homeostasis, platelet aggregation, and transmission of signals by the nervous system. NO is also important for immune system function, playing key roles in the activation of macrophages and cellular defenses against microbial pathogens. Recent studies have revealed that some responses to NO are similar to those among very distantly related organisms; these findings suggest that many of the biological functions of NO have an evolutionarily ancient origin.