Decoding the enigmatic last gasotransmitter. The intriguing journey of HNO: From hidden origins to clues on reactivity and detection

Abstract

This review focuses on HNO, a molecule of immense chemical and biological importance that has intrigued scientists for decades. Despite its elusive and transient nature, HNO may play an important role in various physiological processes, particularly in cardiovascular regulation. This review thoroughly examines the formation, chemical properties, and biological significance of HNO and highlights ongoing research efforts to unravel its mysteries. Challenges in studying HNO arise from its high reactivity, short half-life, and complex interactions with other nitrogen oxides, particularly nitric oxide. Detection and quantification of HNO in biological systems pose difficulties, prompting the development of advanced techniques. Active research into endogenous HNO formation is revealing intricate pathways within biological systems, the elucidation of which is crucial for exploiting its therapeutic potential. The multifaceted role of HNO in cardiovascular regulation, influencing vasorelaxation, blood pressure reduction, and enhanced cardiac contractility, underscores its profound impact on the circulatory system. Ongoing research holds promise for treating conditions such as hypertension and heart failure. As clinical applications expand, HNO research may unlock treatments for cardiovascular disease, inflammatory disorders, and cancer. The recent discovery of endogenous HNO production in plants adds a new dimension. While numerous clues have emerged, the scientific saga underscores that mysteries persist, evolve, and beckon to perpetual exploration in the realm of science.