title: The evolution of nitric oxide signalling in vertebrate blood vessels.
abstract: Nitric oxide is one of the most important signalling molecules involved in the regulation of physiological function. It first came to prominence when it was discovered that the vascular endothelium of mammals synthesises and releases nitric oxide (NO) to mediate a potent vasodilation. Subsequently, it was shown that NO is synthesised in the endothelium by a specific isoform of nitric oxide synthase (NOS) called NOS3. Following this discovery, it was assumed that an endothelial NO/NOS3 system would be present in all vertebrate blood vessels. This review will discuss the latest genomic, anatomical and physiological evidence which demonstrates that an endothelial NO/NOS3 signalling is not ubiquitous in non-mammalian vertebrates, and that there have been key evolutionary steps that have led to the endothelial NO signalling system being a regulatory system found only in reptiles, birds and mammals. Furthermore, the emerging role of nitrite as an endocrine source of NO for vascular regulation is discussed.
authors.affiliation: School of Life and Environmental Sciences, Deakin University, Geelong, VIC, 3217, Australia, jdonald@deakin.edu.au.
authors.forename: John A
authors.initials: JA
authors.lastname: Donald
authors.forename: Leonard G
authors.initials: LG
authors.lastname: Forgan
authors.forename: Melissa S
authors.initials: MS
authors.lastname: Cameron
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000201:enzymology*; D019143:Evolution, Molecular; D009569:Nitric Oxide / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D010802:Phylogeny; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D014714:Vertebrates / Q000097:blood* / Q000145:classification / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III