title: Nitric oxide synthase (NOS) in the human umbilical cord vessels. An immunohistochemical study.
abstract: Localization of nitric oxide synthase (NOS) in endothelial cells of umbilical cord vessels and in cultured human umbilical vein endothelial cells was investigated by light and electron-microscopical (immunogold) immunohistochemistry. We observed localization of NOS-immunoreactivity in the majority (97%) of the endothelial cells of the umbilical vein and in a subpopulation (6.7%) of endothelial cells of the umbilical arteries. NOS was observed as well in the amniotic epithelium and in the cells of Wharton's jelly. Immunogold labelling in human umbilical vein endothelial cells dominated in the cellular matrix and was not associated with cellular organelles. Since human umbilical vessels are unique in lacking innervation, the functional significance of endothelium derived relaxing factor EDRF/NO in the local control of vascular flow is discussed.
authors.affiliation: Department of Anatomy and Histology, Medical University, Varna, Bulgaria.
authors.forename: K
authors.initials: K
authors.lastname: Dikranian
authors.forename: M
authors.initials: M
authors.lastname: Trosheva
authors.forename: S
authors.initials: S
authors.lastname: Nikolov
authors.forename: P
authors.initials: P
authors.lastname: Bodin
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000378:metabolism*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000276:immunology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D019001:Nitric Oxide Synthase; D010920:Placenta / Q000201:enzymology; D011247:Pregnancy; D012039:Regional Blood Flow / Q000502:physiology; D014469:Umbilical Arteries / Q000201:enzymology*; D014471:Umbilical Veins / Q000201:enzymology*
chemical_list: D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases