Nitric Oxide (NO) - "Blood vessel dilator" neurotransmitter

Dubbed “Molecule of the Year” by Science magazine in 1992

Nitric oxide (NO) is NOT the same as nitrous oxide (N₂O, better known as laughing gas)

What is NO?

1 nitrogen atom + 1 oxygen atom
Soluble, highly reactive, short-lived gas

NO production pathways

Produced in certain animal and plant cells from the amino acid L-arginine

Arginine – Precursor to blood vessel dilator Nitric Oxide

Can be derived from nitroglycerine. Well known as a major component of dynamite, but also prescribed in the medical field, E.g. as a nitroglycerine patch. Ironically, Alfred Nobel, the founder of the Nobel Prize,invented dynamite, but did not follow his doctor’s advice to take a compound that signals nitric oxide release for his heart health. It wasn’t until ~ 100 years later it was more fully realized how such products act by releasing nitric oxide gas as a signal molecule.

A byproduct of combustion. Also a product of natural chemical reactions in the atmosphere.

NO has many roles

NO operates as a signaling molecule (neurotransmitter) in brain and immune system. NO signaling efficiency declines with age. NO enhances blood flow and helps maintain optimal blood pressure. The 1998 Nobel Prize winners (Furchgott, Murid, and Ignarro) discovered how endothelial cells produce NO gas to help blood vessels stay relaxed and open for blood flow. These cells lining the blood vessels require the semi-essential amino acid arginine as a precursor for producing NO

Arginine – Precursor to blood vessel dilator Nitric Oxide

Improves all physiological processes by improving both nutrient delivery to cells and cellular waste removal
NO also helps promote healthy blood vessel flexibility and dilation. As a cellular signaling molecule
Sufficient NO reduces risk for coronary artery disease (CAD). Helps keep arteries stay more plaque-free
Good blood flow important in maintaining an erection

Culotta E & Koshland D Jr. (1992) NO news is good news. Science 258 (5090): 1862-1864 Link