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Neuropeptides in the human appendix - Distribution and motor effects

Ekblad, E. LU ; Arnbjörnsson, E. LU ; Ekman, R.; Håkanson, R. and Sundler, F. (1989) In Digestive Diseases and Sciences 34(8). p.1217-1230
Abstract

At present our knowledge of enteric peptide-containing neurons in man is limited. In this study we have used human appendices removed at surgery to examine the peptidergic innervation by immunocytochemistry, immunochemistry, and pharmacological in vitro experiments. Immunocytochemistry revealed a variety of peptide-containing nerve fiber populations in the human appendix. VIP/PHI-, VIP/PHI/NPY-, SP/NKA-, galanin-, and enkephalin-containing nerve fibers were numerous; CGRP- and GRP- containing nerve fibers were moderate in number, while only scattered NPY-, enkephalin/BAM-, and somatostatin-containing nerve fibers could be found. No CCK-, dynorphin A-, or dynorphin B- immunoreactive nerve fibers could be detected. The coexistence of... (More)

At present our knowledge of enteric peptide-containing neurons in man is limited. In this study we have used human appendices removed at surgery to examine the peptidergic innervation by immunocytochemistry, immunochemistry, and pharmacological in vitro experiments. Immunocytochemistry revealed a variety of peptide-containing nerve fiber populations in the human appendix. VIP/PHI-, VIP/PHI/NPY-, SP/NKA-, galanin-, and enkephalin-containing nerve fibers were numerous; CGRP- and GRP- containing nerve fibers were moderate in number, while only scattered NPY-, enkephalin/BAM-, and somatostatin-containing nerve fibers could be found. No CCK-, dynorphin A-, or dynorphin B- immunoreactive nerve fibers could be detected. The coexistence of VIP/PHI, SP/NKA, and enkaphalin/BAM can be anticipated from the known sequence of their respective precursors. However, the coexistence of VIP/PHI and NPY was unexpected but corroborates previous observations in other species. Interestingly, SP and CGRP did not seem to coexist in nerve fibers of the human appendix. Immunochemistry (RIA and HPLC) confirmed the presence of VIP, NPY, SP, galanin, CGRP, GRP, enkephalin, and somatostatin. Motor activity studies suggest that acetylcholine plays a major role in the electrically evoked contractions, since atropine suppressed these contractions. Galanin (10-8-10-6 M) and GRP (10-9-10-7 M) caused concentration-dependent contractions that were unaffected by tetrodotoxin and thus probably reflect a direct action on smooth muscle receptors. GRP (10-9 M) enhanced the electrically induced cholinergic contraction (to 193±24%), while met-enkephalin (10-6 M) reduced it (to 54±6%). Both peptides failed to affect the contractile response to exogenous acetylcholine and probably act to modulate the release of acetylcholine. NPY, VIP, CGRP, SP, and somatostatin failed to induce contraction or to affect the electrically evoked contractions.

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author
organization
publishing date
type
Contribution to journal
publication status
published
keywords
appendix, neuropeptides
in
Digestive Diseases and Sciences
volume
34
issue
8
pages
14 pages
publisher
Springer
external identifiers
  • scopus:0024314976
ISSN
0163-2116
DOI
10.1007/BF01537270
language
English
LU publication?
yes
id
74d067c0-ea3e-4aac-a057-995fd97794f3
date added to LUP
2018-11-09 09:58:42
date last changed
2019-01-06 14:14:14
@article{74d067c0-ea3e-4aac-a057-995fd97794f3,
  abstract     = {<p>At present our knowledge of enteric peptide-containing neurons in man is limited. In this study we have used human appendices removed at surgery to examine the peptidergic innervation by immunocytochemistry, immunochemistry, and pharmacological in vitro experiments. Immunocytochemistry revealed a variety of peptide-containing nerve fiber populations in the human appendix. VIP/PHI-, VIP/PHI/NPY-, SP/NKA-, galanin-, and enkephalin-containing nerve fibers were numerous; CGRP- and GRP- containing nerve fibers were moderate in number, while only scattered NPY-, enkephalin/BAM-, and somatostatin-containing nerve fibers could be found. No CCK-, dynorphin A-, or dynorphin B- immunoreactive nerve fibers could be detected. The coexistence of VIP/PHI, SP/NKA, and enkaphalin/BAM can be anticipated from the known sequence of their respective precursors. However, the coexistence of VIP/PHI and NPY was unexpected but corroborates previous observations in other species. Interestingly, SP and CGRP did not seem to coexist in nerve fibers of the human appendix. Immunochemistry (RIA and HPLC) confirmed the presence of VIP, NPY, SP, galanin, CGRP, GRP, enkephalin, and somatostatin. Motor activity studies suggest that acetylcholine plays a major role in the electrically evoked contractions, since atropine suppressed these contractions. Galanin (10<sup>-8</sup>-10<sup>-6</sup> M) and GRP (10<sup>-9</sup>-10<sup>-7</sup> M) caused concentration-dependent contractions that were unaffected by tetrodotoxin and thus probably reflect a direct action on smooth muscle receptors. GRP (10<sup>-9</sup> M) enhanced the electrically induced cholinergic contraction (to 193±24%), while met-enkephalin (10<sup>-6</sup> M) reduced it (to 54±6%). Both peptides failed to affect the contractile response to exogenous acetylcholine and probably act to modulate the release of acetylcholine. NPY, VIP, CGRP, SP, and somatostatin failed to induce contraction or to affect the electrically evoked contractions.</p>},
  author       = {Ekblad, E. and Arnbjörnsson, E. and Ekman, R. and Håkanson, R. and Sundler, F.},
  issn         = {0163-2116},
  keyword      = {appendix,neuropeptides},
  language     = {eng},
  month        = {08},
  number       = {8},
  pages        = {1217--1230},
  publisher    = {Springer},
  series       = {Digestive Diseases and Sciences},
  title        = {Neuropeptides in the human appendix - Distribution and motor effects},
  url          = {http://dx.doi.org/10.1007/BF01537270},
  volume       = {34},
  year         = {1989},
}