The prize-winning researchers helped elucidate the key role nitric oxide plays as a signalling molecule in the cardiovascular system. Their work showed that NO is not like other signalling molecules. Their discovery that NO gas that is produced by one cell, penetrates through membranes and regulates the function of another cell revealed a new principle for signalling in biological systems. NO differs from other neurotransmitters and hormones in that it is not regulated by storage, release or targeted degradation, but rather solely by synthesis. This discovery is all the more amazing considering that NO, a compound more often associated with air pollution, is very unstable, and is converted to nitrate and nitrite within 10 seconds of its creation.
Nitric oxide is involved in numerous physiological processes.
A lack of nitric oxide in the bloodstream, or a lack of reactivity by the blood vessels to nitric oxide, can narrow the vessel opening, thus raising the blood pressure. When NO is produced by the innermost cell layer of the arteries, the endothelium, it rapidly spreads through the cell membranes to the underlying muscle cells. Their contraction is turned off by NO, resulting in a widening of the arteries. NO has also recently been shown to play a key role in prevention of clot formation in the major vessels of the heart. Nitroglycerine has been prescribed for patients with heart disease since the time of Alfred Nobel, founder of the Nobel Foundation.