NO: the primary EDRF

Since the discovery of an endothelium-derived relaxing factor (EDRF) by Fur chgott and Zawadzki (Furchgott and Zawadzki, 1980), which was later identif ied as nitric oxide (NO) (Ignarro et al., 1987; Palmer el nl., 1987; Furchg ott, 1988), it has become clear that there are a number of additional endot helium-derived vasodilator and vasoconstrictor autacoids (endothelin-1, pro staglandin H-2 and the endothelium-derived hyperpolarizing factor: EDHF). N one of these autacoids play such a central role in the regulation of vascul ar tone and homeostasis as the primary EDRF, the free radical NO, which is generated via a five-electron oxidation of a guanidino nitrogen from L-argi nine by an NO synthase (NOS). (C) 1999 Academic Press.