How ubiquitous is endothelial NOS?

Fahima Syeda, David Hauton, Steven Young, Stuart Egginton

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)
255 Downloads (Pure)


The ability to regulate vascular tone is an essential cardiovascular control mechanism, with nitric oxide (NO) assumed to be a ubiquitous smooth muscle relaxant. However, the literature contains reports of vasoconstrictor, vasodilator and no response to nitroergic stimulation in non-mammalian vertebrates. We examined functional (branchial artery myography), structural (immunohistochemistry of skeletal muscle), proteomic (Western analysis) and genomic (RT-PCR, sequence orthologues, syntenic analysis) evidence for endothelial NO synthase (NOS3) in model and non-model fish species. A variety of nitrodilators failed to elicit any changes in vascular tone, although a dilatation to exogenous cyclic GMP was noted. NOS3 antibody staining does not localise to endothelial markers in cryosections, and gives rise to non-specific staining of Western blots. Abundant NOS2 mRNA was found in all species but NOS3 was not found in any fish, while putative orthologues are not flanked by similar genes to NOS3 in humans. We conclude that NOS3 does not exist in fish, and that previous reports of its presence may reflect use of antibodies raised against mammalian epitopes.
Original languageEnglish
Pages (from-to)207-214
JournalComparative Biochemistry and Physiology - Part A: Molecular & Integrative Physiology
Issue number1
Early online date30 May 2013
Publication statusPublished - Sept 2013


  • Capillaries
  • eNOS
  • Fish
  • Histochemistry
  • Muscle
  • Myography
  • Synteny


Dive into the research topics of 'How ubiquitous is endothelial NOS?'. Together they form a unique fingerprint.

Cite this