Nitric oxide producing neurons in the human colon: an immunohistochemical and histoenzymatical study

Neurosci Lett. 1995 Jun 23;193(1):17-20. doi: 10.1016/0304-3940(95)11655-g.


The nitric oxide producing neurons of the human colonic myenteric plexus have been studied by using antibodies against cerebellar NO synthase type I (NOS-IR) and NADPH-diaphorase (NAPDH-d) histoenzymatic reaction. The majority of the stained neurons were both NOS-IR and NADPH-d-positive, while a few others were either NADPH-d-positive or NOS-IR only. Among the co-stained neurons, four subpopulations sharing various degrees of staining intensities have been identified. These findings indicate that in the human colon a one-to-one correlation between NOS-IR and NADPH-d positivity does not exist and thus the NADPH-d reaction does not delineate with certainty all NO-producing neurons. The degree of staining intensity might account for different intracellular amounts of these two enzymes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies / immunology
  • Colon / enzymology*
  • Colon / metabolism*
  • Enzyme Activation
  • Humans
  • Immunohistochemistry
  • Myenteric Plexus / immunology
  • Myenteric Plexus / metabolism
  • NADP / metabolism
  • Neurons / metabolism*
  • Nitric Oxide / biosynthesis*


  • Antibodies
  • Nitric Oxide
  • NADP