In mammals, nitric oxide (NO) is a chemical compound that acts as a cell signaling molecule in different physiological and pathological processes. Nitric oxide levels in the body can be affected by many factors, such as allergies, insufficient iron in the blood, exposure to carbon monoxide, oxygen deficiency, and an excess of estrogen. Nitric oxide is also an air pollutant and nitric oxide levels in the atmosphere are determined by the number of automobiles and power plants using fossil fuel for combustion.
Nitric oxide is a neurotransmitter that is produced in various sites in the body from the breaking down of the amino acid, arginine. At an appropriate level, one of its beneficial functions is vasodilation, which can aid in conditions like chest pain, clogged arteries, erectile dysfunction, heart failure, and headaches due to vascular swelling. It can also promote dilation of the uterus during childbirth, retard bone resorption, and destroy bacteria, fungi, and tumor cells. High nitric oxide levels, however, can be dangerous. With the ability to actually kill neurons, it is believed to be complicit in the deterioration that occurs in individuals who have suffered a stroke.
Exercise has also been found to increase the nitric oxide levels in the body. One of the reasons that doctors promote a more active lifestyle is because nitric oxide acts as an antiatherogenic, which means that it protects the lining of the arteries. It does this by working to prevent the red blood cells from clumping or sticking together and attaching to the walls of the blood vessels. As a result, this decreases the chances of developing heart disease.
Nitric oxide levels are also affected by the presence of antioxidants. These are best known for their ability to protect the cells against the effects of free radicals. When antioxidants are present in the body in the form of vitamins like A and C, the rate of oxidation, which is the breakdown of nitric oxide, is slowed or even prevented.
After scientists Louis Ignarro, Robert Furchgott and Ferid Murad won the Nobel Prize for demonstrating the life-saving properties of nitric oxide, it was named 1992 Molecule of the Year by Science Journal. It wasn’t long before the potential benefits of artificially manipulating nitric oxide levels became apparent. Dozens of nitric-oxide based supplements and products are now available on the market. Perhaps the best known example is in the area of erectile dysfunction.