title: Nitric oxide synthase in neurons of the human gall-bladder and its colocalization with neuropeptides.
abstract: The distributions of nerve cells and fibres that are immunoreactive for nitric oxide synthase (NOS) have been investigated in the human gall-bladder. In addition, the colocalization of NOS immunoreactivity (IR) with neuropeptide Y (NPY), pituitary adenylyl cyclase activating peptide (PACAP), somatostatin (SOM), substance P (SP), tyrosine hydroxylase (TH) and vasoactive intestinal peptide (VIP)-IR was determined. Nitric oxide synthase-IR nerve cell bodies comprised 13 and 30% of nerve cells in ganglia of the fibromuscular and subepithelial layers, respectively. To determine these percentages, neuron-specific enolase-IR was used as a marker for all nerve cells. Although SOM- and VIP-IR nerve cell bodies were found in both ganglia, they rarely contained NOS-IR. In the fibromuscular layer, NOS-IR nerve fibres were abundant and most PACAP-, SOM- and VIP-IR fibres and many NPY-IR fibres were also NOS positive. No colocalization was observed between NOS- and SP- or TH-IR. In the mucosal layer, moderate numbers of NOS-IR fibres were found and the degree of colocalization of NOS-IR with each of NPY-, PACAP-, SOM-, SP- and VIP-IR were as follows: PACAP and NPY > VIP > SOM and SP. Nitric oxide synthase and TH were not colocalized in mucosal fibres. These results suggest that nerve fibres in the fibromuscular layer in the human gall-bladder with the chemical coding NOS/NPY/PACAP/SOM/VIP are axons of inhibitory motor neurons. Nitric oxide synthase-IR fibres in the mucosal layer that contained NPY, PACAP, SOM, SP and VIP with various degrees of colocalization probably contribute to the control of epithelial secretion or absorption.
authors.affiliation: Department of Anatomy and Cell Biology, University of Melbourne, Austin Hospital, Heidelberg, Victoria, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Uemura
authors.forename: S
authors.initials: S
authors.lastname: Pompolo
authors.forename: J B
authors.initials: JB
authors.lastname: Furness
authors.forename: K J
authors.initials: KJ
authors.lastname: Hardy
mesh_terms: D005704:Gallbladder / Q000294:innervation*; D005724:Ganglia / Q000033:anatomy & histology; D006801:Humans; D007150:Immunohistochemistry; D009412:Nerve Fibers / Q000648:ultrastructure; D009474:Neurons / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D009479:Neuropeptides; D019001:Nitric Oxide Synthase; D010751:Phosphopyruvate Hydratase