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Intestinal adaptation in atrophic rat ileum is accompanied by supersensitivity to vasoactive intestinal peptide, pituitary adenylate cyclase-activating peptide and nitric oxide

Ekelund, M and Ekblad, Eva LU (2001) In Scandinavian Journal of Gastroenterology 36(3). p.251-257
Abstract
BACKGROUND: Intestinal inactivity leads to atrophic changes and concomitant alterations in the expression of neurotransmitters in the enteric nervous system. In atrophic rat ileum neurones expressing vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP) decrease in number while nitric oxide synthase (NOS) expressing neurones increase. Since little is known about functional changes accompanying intestinal atrophy the aim of the present study was to investigate relaxatory responses to VIP, PACAP-27 and nitric oxide (NO) in longitudinal smooth muscle from atrophic rat ileum. METHODS: To create a dysfunctional (atrophic) intestine, the distal 10 cm of rat ileum was surgically bypassed. In vitro... (More)
BACKGROUND: Intestinal inactivity leads to atrophic changes and concomitant alterations in the expression of neurotransmitters in the enteric nervous system. In atrophic rat ileum neurones expressing vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP) decrease in number while nitric oxide synthase (NOS) expressing neurones increase. Since little is known about functional changes accompanying intestinal atrophy the aim of the present study was to investigate relaxatory responses to VIP, PACAP-27 and nitric oxide (NO) in longitudinal smooth muscle from atrophic rat ileum. METHODS: To create a dysfunctional (atrophic) intestine, the distal 10 cm of rat ileum was surgically bypassed. In vitro experiments were carried out on longitudinal muscle strips from rat ileum having been sham-operated, one week or four weeks bypassed. RESULTS: The amplitudes of the relaxatory responses to PACAP-27, VIP and the NO-donor S-nitroso-N-acetylpenicillamine (SNAP), but not forskolin, were significantly increased in the one-week bypassed ileum. In the four-weeks bypassed ileum the VIP, PACAP-27, SNAP and forskolin evoked relaxations were of the same magnitude as those of the sham-operated. The augmented responses to both VIP and PACAP-27 could be blocked by pre-treatment with apamin while N(G)-nitro-L-arginine methyl ester (L-NAME) and tetrodotoxin were ineffective. In contrast to sham-operated and four-weeks bypassed ileum, cross-desensitization between VIP and PACAP-27 was noted after one week of bypass. CONCLUSION: Intestinal adaptation after bypassing the distal ileum of the rat includes a transient supersensitivity of the longitudinal muscle to the NO donor SNAP, VIP and PACAP-27. These augmented relaxatory responses may contribute to the hypomotility noted in inactive intestine. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Oxide, Apamin, Ileal, Bypass, Intestinal, Relaxation, Adaptation, Supersensitivity, Nitric, Pacap, Cyclase-ACTIVATING, Peptide, Adenylate, Pituitary, Vip, Vasoactive
in
Scandinavian Journal of Gastroenterology
volume
36
issue
3
pages
251 - 257
publisher
Taylor & Francis
external identifiers
  • pmid:11305511
  • scopus:0035087023
ISSN
1502-7708
DOI
10.1080/00365520116742
language
English
LU publication?
yes
id
f75b3439-6cf1-4caf-84d0-4ad1e05208d1 (old id 1120524)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/11305511
date added to LUP
2008-06-26 14:51:24
date last changed
2018-05-29 10:17:35
@article{f75b3439-6cf1-4caf-84d0-4ad1e05208d1,
  abstract     = {BACKGROUND: Intestinal inactivity leads to atrophic changes and concomitant alterations in the expression of neurotransmitters in the enteric nervous system. In atrophic rat ileum neurones expressing vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP) decrease in number while nitric oxide synthase (NOS) expressing neurones increase. Since little is known about functional changes accompanying intestinal atrophy the aim of the present study was to investigate relaxatory responses to VIP, PACAP-27 and nitric oxide (NO) in longitudinal smooth muscle from atrophic rat ileum. METHODS: To create a dysfunctional (atrophic) intestine, the distal 10 cm of rat ileum was surgically bypassed. In vitro experiments were carried out on longitudinal muscle strips from rat ileum having been sham-operated, one week or four weeks bypassed. RESULTS: The amplitudes of the relaxatory responses to PACAP-27, VIP and the NO-donor S-nitroso-N-acetylpenicillamine (SNAP), but not forskolin, were significantly increased in the one-week bypassed ileum. In the four-weeks bypassed ileum the VIP, PACAP-27, SNAP and forskolin evoked relaxations were of the same magnitude as those of the sham-operated. The augmented responses to both VIP and PACAP-27 could be blocked by pre-treatment with apamin while N(G)-nitro-L-arginine methyl ester (L-NAME) and tetrodotoxin were ineffective. In contrast to sham-operated and four-weeks bypassed ileum, cross-desensitization between VIP and PACAP-27 was noted after one week of bypass. CONCLUSION: Intestinal adaptation after bypassing the distal ileum of the rat includes a transient supersensitivity of the longitudinal muscle to the NO donor SNAP, VIP and PACAP-27. These augmented relaxatory responses may contribute to the hypomotility noted in inactive intestine.},
  author       = {Ekelund, M and Ekblad, Eva},
  issn         = {1502-7708},
  keyword      = {Oxide,Apamin,Ileal,Bypass,Intestinal,Relaxation,Adaptation,Supersensitivity,Nitric,Pacap,Cyclase-ACTIVATING,Peptide,Adenylate,Pituitary,Vip,Vasoactive},
  language     = {eng},
  number       = {3},
  pages        = {251--257},
  publisher    = {Taylor & Francis},
  series       = {Scandinavian Journal of Gastroenterology},
  title        = {Intestinal adaptation in atrophic rat ileum is accompanied by supersensitivity to vasoactive intestinal peptide, pituitary adenylate cyclase-activating peptide and nitric oxide},
  url          = {http://dx.doi.org/10.1080/00365520116742},
  volume       = {36},
  year         = {2001},
}