Nitriittioksidi

Nitriittioksidi, also known as nitric oxide or NO, is a colorless gas with the chemical formula NO. It is a molecule produced by living organisms, including humans, and plays a crucial role in various physiological processes. In mammals, NO is synthesized from the amino acid L-arginine by a family of enzymes called nitric oxide synthases (NOS).

NO acts as a signaling molecule, a neurotransmitter, and a vasodilator. As a vasodilator, it relaxes smooth muscles in blood vessel walls, leading to increased blood flow and lower blood pressure. This property makes it important for regulating cardiovascular function. In the nervous system, NO is involved in processes like learning, memory, and pain perception. It can also play a role in immune responses, helping to kill pathogens.

The production and action of NO are tightly regulated. While essential for many bodily functions, excessive or insufficient levels of NO can be detrimental. For example, chronic inflammation can lead to overproduction of NO, which can damage tissues. Conversely, impaired NO production is implicated in conditions like hypertension and atherosclerosis.

Nitriittioksidi is also a component of air pollution, formed during combustion processes. In the atmosphere, it can contribute to the formation of smog and acid rain. Its chemical reactivity means it is quickly converted into other nitrogen oxides.