Gasotransmitters are gas

Gas

Gas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...

eous molecule

Molecule

A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...

s synthesized in the body. They include nitric oxide

Nitric oxide

Nitric oxide, also known as nitrogen monoxide, is a diatomic molecule with chemical formula NO. It is a free radical and is an important intermediate in the chemical industry...

, hydrogen sulfide

Hydrogen sulfide

Hydrogen sulfide is the chemical compound with the formula . It is a colorless, very poisonous, flammable gas with the characteristic foul odor of expired eggs perceptible at concentrations as low as 0.00047 parts per million...

, carbon monoxide

Carbon monoxide

Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...

, and possibly nitrous oxide

Nitrous oxide

Nitrous oxide, commonly known as laughing gas or sweet air, is a chemical compound with the formula . It is an oxide of nitrogen. At room temperature, it is a colorless non-flammable gas, with a slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic...

.

Overview

Gasotransmitters is a family of endogenous molecules of gases or gaseous signaling molecules, including NO, CO, H₂S, and others. These particular gases share many common features in their production and function but carry on their tasks in unique ways, which differ from classical signaling molecules, in the human body. The first suggestion that a gas, , had a direct action at pharmacological receptors and thereby acting as a neurotransmitter was first suggested in 1981 from clinical work with nitrous oxide (1,2,3). In vitro experiments confirmed these observations (4) which were replicated at NIDA later(5).

The terminology and characterization criteria of “gasotransmitter” were firstly introduced in 2002 (see ref. 14). For one gas molecule to be categorized as a gasotransmitters, all of the following criteria should be met (see ref. 13 &14). (i) It is a small molecule of gas; (ii) It is freely permeable to membranes. As such, its effects do not rely on the cognate membrane receptors. It can have endocrine, paracrine, and autocrine effects. In their endocrine mode of action, for example, gasotransmitters can enter the blood stream; be carried to remote targets by scavengers and released there, and modulate functions of remote target cells; (iii) It is endogenously and enzymatically generated and its production is regulated; (iv) It has well defined and specific functions at physiologically relevant concentrations. Thus, manipulating the endogenous levels of this gas evokes specific physiological changes; (v) Functions of this endogenous gas can be mimicked by its exogenously applied counterpart; (vi) Its cellular effects may or may not be mediated by second messengers, but should have specific cellular and molecular targets.