Discovery of Some of the Biological Effects of Nitric Oxide and Its Role in Cell Signaling (Nobel Lecture)

A unique simple molecule with an array of signaling functions: NO. The free radical nitric oxide not only mediates a long list of biological effects by activating guanylyl cyclase and increasing cyclic GMP synthesis from GTP, but can also interact with transition metals such as iron, thiol groups, other free radicals, oxygen, superoxide anion, unsaturated fatty acids, and other molecules. Furthermore, NO can function as an intracellular messenger, an autacoid, a paracrine substance, a neurotransmitter, or a hormone that can be carried to distant sites for effects.