Nitric Oxide

The 1998 nobel prize in medicine was awared to Murade, Ignarro and Ferchgott on

Nitrogen Mono-oxide as a signal molecule in the cardiovascular system.

NO is a short lived compound with a lifetime of about 10 seconds, the life cycle and affects of NO sythesized in the endothelial cell are summarised in figure 9. Synthesis of NO also occurs in nerve cells and macrophages. The biological functions discovered so far for NO are;

In macrophages and monocytes

provides their cytotoxic and cytostatic activities against foreign cells, including microbes, and activates T lymphocyts and immunoglobulin E.

In endothelial cells

acts as a vasodilator, platlet and red blood cell antiaggregant, and thrombus formation inhibitor.

In the nervous system

act as a neurotransmitter and affects synaptic plasticity and is involved in memory.

In smooth muscles

as a muscle relaxant in the digestive tract and bronchi.

NO is used clinically to treat pulmonary hypetension and the respiratory distress syndrome. It may also play a role in wound healing.