title: [Endogenously formed nitric oxide in nasal mucosa of the human: detection by nicotinamide-adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry].
abstract: BACKGROUND
  Nitric oxide (NO) is an intercellular transmitter, both in the central and in the peripheral nervous system. In addition to nerve cells, NO is also produced in epithelial cells of various tissues and in the endothelium. NO is formed by the action of nitric oxide synthase (NOS). There is evidence that NOS can be marked by NADPH-diaphorase (NADPH-d) activity in many cell types. The aim of this study was to identify NOS-positive structures in human nasal mucosa by using NADPH-d-histochemistry.
  
  
  METHODS
  Frozen sections from inferior turbinates were fixed with buffered formalin and then treated according to the description of Vincent and Kimura. Additionally, the same sections underwent a double staining procedure for acetylcholinesterase (Karnovski-Roots) to show a correlation with cholinergic nerve structures.
  
  
  RESULTS
  Strong reactions were found in the epithelium and in nerve fibres, compared to less NADPH-d activity in seromucous glands and the endothelium of the different vessel types. Singular NADPH-d positive nerves were found within nerve bundles, periarterially, in the subepithelial layer and surrounding glands and their ducts. A frequent localisation of NADPH-d could be detected in parasympathetic nerve fibres.
  
  
  CONCLUSIONS
  The occurrence of NADPH-d in epithelial, glandular and nerval structures suggests that NOS takes part in physiological functions and possible pathophysiological processes of the nose. Similar to findings in various other organs this investigation demonstrated that the neurotransmitter NO can also be associated with the parasympathetic nervous system in the human nasal mucosa.
authors.affiliation: Klinik und Poliklinik für HNO-Kranke der Ludwig-Maximilians-Universität, München.
authors.forename: A
authors.initials: A
authors.lastname: Riederer
authors.forename: B
authors.initials: B
authors.lastname: Held
authors.forename: J
authors.initials: J
authors.lastname: Wörl
authors.forename: J
authors.initials: J
authors.lastname: Unger
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000328:Adult; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D009252:NADPH Dehydrogenase / Q000378:metabolism*; D009297:Nasal Mucosa / Q000294:innervation* / Q000473:pathology; D015508:Nasal Obstruction / Q000201:enzymology / Q000473:pathology; D009412:Nerve Fibers / Q000201:enzymology / Q000473:pathology; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D014420:Turbinates / Q000294:innervation / Q000473:pathology
chemical_list: D019001:Nitric Oxide Synthase; D009252:NADPH Dehydrogenase; D000110:Acetylcholinesterase