Nitrogen (N)

Nitrogen is a fundamental chemical element (atomic number 7) that predominantly exists as a diatomic gas (N2), making up approximately 78% of Earth's atmosphere [1]. While nitrogen atoms are essential building blocks for all proteins and nucleic acids in the human body, elemental nitrogen is biologically inert and is not recognized as a molecular drug target such as a receptor, enzyme, or transporter [2]. Clinically, its primary use is in the liquid state for cryotherapy (cryosurgery), where it serves as a cooling agent to induce localized tissue destruction (cryonecrosis) for the treatment of various skin pathologies and some internal tumors [3]. Beyond its use in cryosurgery, nitrogen gas can pose significant health risks in specialized environments, such as nitrogen narcosis in deep-sea diving or asphyxiation in low-oxygen settings [4]. Because it is a basic element and not a specific protein or signaling molecule, it does not fit the standard definition of a therapeutic target in drug development [1][2]. Sources: [1] PubChem, Compound Summary: Nitrogen (CID 5362570). [2] National Center for Biotechnology Information (NCBI), Biochemistry of Nitrogen and amino acids. [3] StatPearls, Cryosurgery (Liquid Nitrogen). [4] National Institutes of Health (NIH), Nitrogen Narcosis and Decompression Sickness.

Other names

N2DinitrogenLiquid nitrogenAzote

Nitrogen itself does not have a molecular mechanism of action as a drug target. However, in cryotherapy, liquid nitrogen induces therapeutic cryonecrosis through the rapid freezing of intracellular and extracellular water, leading to cell membrane rupture, protein denaturation, and localized vascular stasis [3].