uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Gut peptides in gastrointestinal motility and mucosal permeability
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Gastroenterology/Hepatology. Uppsala University. (Gastroenterology & Hepatology)ORCID iD: 0000-0001-6220-3936
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Gut regulatory peptides, such as neuropeptides and incretins, play important roles in hunger, satiety and gastrointestinal motility, and possibly mucosal permeability. Many peptides secreted by myenteric nerves that regulate motor control are also produced in mucosal epithelial cells. Derangements in motility and mucosal permeability occur in many diseases. Current knowledge is fragmentary regarding gut peptide actions and mechanisms in motility and permeability.

This thesis aimed to 1) develop probes and methods for gut permeability testing, 2) elucidate the role of neuropeptide S (NPS) in motility and permeability, 3) characterize nitrergic muscle relaxation and 4) characterize mechanisms of glucagon-like peptide 1 (GLP-1) and the drug ROSE-010 (GLP-1 analog) in motility inhibition.

A rapid fluorescent permeability test was developed using riboflavin as a transcellular transport probe and the bisboronic acid 4,4'oBBV coupled to the fluorophore HPTS as a sensor for lactulose, a paracellular permeability probe. This yielded a lactulose:riboflavin ratio test.

NPS induced muscle relaxation and increased permeability through NO-dependent mechanisms. Organ bath studies revealed that NPS induced NO-dependent muscle relaxation that was tetrodotoxin (TTX) sensitive. In addition to the epithelium, NPS and its receptor NPSR1 localized at myenteric nerves. Circulating NPS was too low to activate NPSR1, indicating NPS uses local autocrine/paracrine mechanisms.

Nitrergic signaling inhibition by nitric oxide synthase inhibitor L-NMMA elicited premature duodenojejunal phase III contractions in migrating motility complex (MMC) in humans. L-NMMA shortened MMC cycle length, suppressed phase I and shifted motility towards phase II. Pre-treatment with atropine extended phase II, while ondansetron had no effect. Intestinal contractions were stimulated by L-NMMA, but not TTX. NOS immunoreactivity was detected in the myenteric plexus but not smooth muscle.

Food-intake increased motility of human antrum, duodenum and jejunum. GLP-1 and ROSE-010 relaxed bethanechol-induced contractions in muscle strips. Relaxation was blocked by GLP-1 receptor antagonist exendin(9-39) amide, L-NMMA, adenylate cyclase inhibitor 2´5´-dideoxyadenosine or TTX. GLP-1R and GLP-2R were expressed in myenteric neurons, but not muscle.

In conclusion, rapid chemistries for permeability were developed while physiological mechanisms of NPS, nitrergic and GLP-1 and ROSE-010 signaling were revealed. In the case of NPS, a tight synchrony between motility and permeability was found.

 

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2016. , 58 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 1233
Keyword [en]
Gut regulatory peptides, Neuropeptides, Gastrointestinal mucosal permeability, Gastrointestinal motility, GLP-1, NPS, ROSE-010
National Category
Medical and Health Sciences
Identifiers
URN: urn:nbn:se:uu:diva-294390ISBN: 978-91-554-9607-4 (print)OAI: oai:DiVA.org:uu-294390DiVA: diva2:929780
Public defence
2016-06-14, Enghoffsalen, Entrance 50, Uppsala University Hospital, Uppsala, 09:00 (English)
Opponent
Supervisors
Available from: 2016-05-24 Created: 2016-05-19 Last updated: 2016-06-15
List of papers
1. Rapid small intestinal permeability assay based on riboflavin and lactulose detected by bis-boronic acid appended benzyl viologens
Open this publication in new window or tab >>Rapid small intestinal permeability assay based on riboflavin and lactulose detected by bis-boronic acid appended benzyl viologens
Show others...
2015 (English)In: Clinica Chimica Acta, ISSN 0009-8981, E-ISSN 1873-3492, Vol. 439, 115-121 p.Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Although organoboronic acids are efficient high-throughput sugar sensors, they have not been pursued for gut permeability studies. A modification of the lactulose/mannitol assay is described by which small intestinal permeability is assessed at the time of urine collection using a lactulose/riboflavin ratio.

METHODS: Volunteers ingested 50mg riboflavin and either 5g mannitol or 10g lactulose. Urine was collected for 6hrs. Riboflavin was assayed by autofluorescence. Riboflavin was removed by C18 solid phase extraction. Lactulose and mannitol were then assayed using 1,1'-bis(2-boronobenzyl)-4,4'-bipyridinium (4,4'oBBV) coupled to the fluorophore HPTS.

RESULTS: The temporal profile over 6hrs for riboflavin paralleled mannitol. Riboflavin recovery in urine was 11.1±1.9 % (mean±SEM, n=7), similar to mannitol. There was selective binding of 4,4'oBBV to lactulose, likely involving cooperativity between the fructose and galactose moieties. Lower limits of detection and quantification were 90 and 364μM. The lactulose assay was insensitive to other permeability probes (e.g., sucrose, sucralose) while tolerating glucose or lactose. This assay can be adapted to automated systems. Stability of 4,4'oBBV exceeds 4years.

CONCLUSIONS: Riboflavin measured by autofluorescence combined with lactulose measured with 4,4'oBBV represents a useful new chemistry for rapid measurement of intestinal permeability with excellent stability, cost and throughput benefits.

Keyword
Intestinal permeability, Organoborane, Gastroenterology, Lactulose, Mannitol, Riboflavin
National Category
Gastroenterology and Hepatology
Identifiers
urn:nbn:se:uu:diva-236349 (URN)10.1016/j.cca.2014.09.031 (DOI)000347499700021 ()25300228 (PubMedID)
Note

De två första författarna delar första författarskapet.

Available from: 2014-11-18 Created: 2014-11-18 Last updated: 2017-12-05Bibliographically approved
2. Neuropeptide S inhibits gastrointestinal motility and increases mucosal permeability through nitric oxide
Open this publication in new window or tab >>Neuropeptide S inhibits gastrointestinal motility and increases mucosal permeability through nitric oxide
Show others...
2015 (English)In: American Journal of Physiology - Gastrointestinal and Liver Physiology, ISSN 0193-1857, E-ISSN 1522-1547, Vol. 309, no 8, G625-G634 p.Article in journal (Refereed) Published
Abstract [en]

Neuropeptide S (NPS) receptor (NPSR1) polymorphisms are associated with enteral dysmotility and inflammatory bowel disease (IBD). This study investigated the role of NPS in conjunction with nitrergic mechanisms in the regulation of intestinal motility and mucosal permeability. In rats, small intestinal myoelectric activity and luminal pressure changes in small intestine and colon, along with duodenal permeability were studied. In human intestine, NPS and NPSR1 were localized by immunostaining. Pre- and postprandial plasma NPS was measured by ELISA in healthy and active IBD humans. Effects and mechanisms of NPS were studied in human intestinal muscle strips. In rats, NPS 100-4000 pmol/kg·min had effects on the small intestine and colon. Low doses of NPS increased myoelectric spiking (p<0.05). Higher doses reduced spiking and prolonged the cycle length of the migrating myoelectric complex, reduced intraluminal pressures (p<0.05-0.01) and increased permeability (p<0.01) through NO-dependent mechanisms. In human intestine, NPS localized at myenteric nerve cell bodies and fibers. NPSR1 was confined to nerve cell bodies. Circulating NPS in humans was tenfold below the ~0.3 nmol/l dissociation constant (Kd) of NPSR1, with no difference between healthy and IBD subjects. In human intestinal muscle strips pre-contracted by bethanechol, NPS 1-1000 nmol/l induced NO-dependent muscle relaxation (p<0.05) that was sensitive also to tetrodotoxin (p<0.01). In conclusion, NPS inhibits motility and increases permeability in neurocrine fashion acting through NO in the myenteric plexus in rats and humans. Aberrant signaling and up-regulation of NPSR1 could potentially exacerbate dysmotility and hyperpermeability by local mechanisms in gastrointestinal functional and inflammatory reactions.

Keyword
inflammation; inflammatory bowel disease; migrating motor complex; NO; peristalsis
National Category
Physiology
Identifiers
urn:nbn:se:uu:diva-264766 (URN)10.1152/ajpgi.00104.2015 (DOI)000364068300002 ()26206857 (PubMedID)
Funder
The Swedish Medical Association, SLS-176671Swedish Research Council, 7916Swedish Society of Medicine, SLS-176671Swedish National Board of Health and Welfare, SLS-176671
Note

Shared first name: Wan Salman Wan Saudi and Md. Abdul Halim.

Shared last name: Dominic-Luc Webb, Markus Sjöblom and Per M. Hellström.

Available from: 2015-10-16 Created: 2015-10-16 Last updated: 2017-12-01Bibliographically approved
3. Nitric oxide regulation of migrating motor complex: randomised trial of L-NMMA effects in relation to muscarinic and serotonergic receptor blockade
Open this publication in new window or tab >>Nitric oxide regulation of migrating motor complex: randomised trial of L-NMMA effects in relation to muscarinic and serotonergic receptor blockade
Show others...
2015 (English)In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 215, no 2, 105-118 p.Article in journal (Refereed) Published
Abstract [en]

Aim

The migrating motor complex (MMC) propels contents through the gastrointestinal tract during fasting. Nitric oxide (NO) is an inhibitory neurotransmitter in the gastrointestinal tract. Little is known about how NO regulates the MMC. In this study, the aim was to examine nitrergic inhibition of the MMC in man using NG-monomethyl-l-arginine (l-NMMA) in combination with muscarinic receptor antagonist atropine and 5-HT3 receptor antagonist ondansetron.

Methods

Twenty-six healthy volunteers underwent antroduodenojejunal manometry for 8 h with saline or NO synthase (NOS) inhibitor l-NMMA randomly injected I.V. at 4 h with or without atropine or ondansetron. Plasma ghrelin, motilin and somatostatin were measured by ELISA. Intestinal muscle strip contractions were investigated for NO-dependent mechanisms using l-NMMA and tetrodotoxin. NOS expression was localized by immunohistochemistry.

Results

l-NMMA elicited premature duodenojejunal phase III in all subjects but one, irrespective of atropine or ondansetron. l-NMMA shortened MMC cycle length, suppressed phase I and shifted motility towards phase II. Pre-treatment with atropine extended phase II, while ondansetron had no effect. l-NMMA did not change circulating ghrelin, motilin or somatostatin. Intestinal contractions were stimulated byl-NMMA, insensitive to tetrodotoxin. NOS immunoreactivity was detected in the myenteric plexus but not in smooth muscle cells.

Conclusion

Nitric oxide suppresses phase III of MMC independent of muscarinic and 5-HT3 receptors as shown by nitrergic blockade, and acts through a neurocrine disinhibition step resulting in stimulated phase III of MMC independent of cholinergic or 5-HT3-ergic mechanisms. Furthermore, phase II of MMC is governed by inhibitory nitrergic and excitatory cholinergic, but not 5-HT3-ergic mechanisms.

Keyword
motility, myenteric plexus, NG-monomethyl-l-arginine, nitric oxide, nitric oxide synthase
National Category
Gastroenterology and Hepatology
Research subject
Medical Science
Identifiers
urn:nbn:se:uu:diva-259469 (URN)DOI:10.1111/apha.12554 (DOI)
Funder
Swedish Research Council, 7916
Note

De 2 första författarna delar förstaförfattarskapet.

The study was supported by Swedish Research Council (7916), Uppsala University (540113) and the Erik, Karin och Gösta Selander Fund (14-03-07)

Available from: 2015-08-04 Created: 2015-08-04 Last updated: 2017-12-04Bibliographically approved
4. GLP-1 acts at myenteric neurons to inhibit motility in humans: results of in vivo motility studies and in vitro characterization of responses to GLP-1 and ROSE-010: GLP-1 and digestive motility
Open this publication in new window or tab >>GLP-1 acts at myenteric neurons to inhibit motility in humans: results of in vivo motility studies and in vitro characterization of responses to GLP-1 and ROSE-010: GLP-1 and digestive motility
Show others...
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Background: Glucagon-like peptide-1 (GLP-1) is secreted from L-cells after nutrient ingestion, inhibiting motility. Aims: To clarify whether infused GLP-1 inhibits in vivo prandial motility response and determine the likeliest target cell type and mechanism of action of GLP-1 and its analogue ROSE-010 using in vitro human gut muscle strips. Methods: Sixteen healthy volunteers underwent antroduodenojejunal manometry. Recordings of 1 hour infusion of saline or GLP-1 (0.7 or 1.2 pmol/kg/min) were compared. Plasma GLP-1 and GLP-2 were measured by RIA. Gastrointestinal muscle strips from surgical re-sections, pre-contracted with bethanechol or electric field stimulation (EFS), were investigated for GLP-1 or ROSE-010 induced relaxation. Receptors for GLP-1 and GLP-2 (GLP-1R, GLP-2R) were visualized by immunohistochemistry. Mechanisms were studied employing exendin(9-39) amide, Lw-nitro-monomethyl arginine (L-NMMA), 2´5´-dideoxyadenosine (DDA) and tetrodotoxin (TTX). Results: Food-intake increased motility index from 4.0±0.5 to 6.4±0.3 (antrum), 4.2±0.4 to 5.7±0.4 (duodenum) and 4.6±0.3 to 5.9±0.2 (jejunum) ln(Σ(mmHg·s·min-1)). GLP-1 at 0.7 pmol/kg/minwas sufficient to suppress these indexes from 6.2±0.4 to 3.8±0.7, 5.6±0.6 to 3.9±0.6 and 5.8±0.1 to 4.6±0.4 ln(Σ(mmHg·s·min-1)). Both GLP-1 doses raised plasma GLP-1, but not GLP-2. GLP-1 (EC50 40 nM) and ROSE-010 (EC50 50 nM) relaxed bethanechol-induced contractions in muscle strips. Inhibitory responses were blocked by exendin(9-39) amide, L-NMMA, DDA or TTX pre-treatment. GLP-1R and GLP-2R were expressed in myenteric neurons, but not muscle. Conclusions: GLP-1 and ROSE-010 inhibit motility through GLP-1R at myenteric neurons, which also possess GLP-2 receptors. GLP-1 increases more than GLP-2 with meals and does not increase plasma GLP-2. GLP-1 and ROSE-010 relaxations are cAMP and NO dependent.

Keyword
Antroduodenojejunal motility, Glucagon-like peptides, Peptide hormones, ROSE-010, exendin(9-39) amide
National Category
Medical and Health Sciences
Research subject
Physiology
Identifiers
urn:nbn:se:uu:diva-294388 (URN)
Available from: 2016-05-19 Created: 2016-05-19 Last updated: 2016-05-25

Open Access in DiVA

fulltext(1061 kB)357 downloads
File information
File name FULLTEXT01.pdfFile size 1061 kBChecksum SHA-512
0dc140c81a01cd83ac31685958b94c2d7fb4968ae71b1cf4098ac0ddb27b19b617146fb27ccbfd04597123a388061cd040630afb48fd1f88de22921dba9b8de1
Type fulltextMimetype application/pdf
Buy this publication >>

Authority records BETA

Halim, Md. Abdul

Search in DiVA

By author/editor
Halim, Md. Abdul
By organisation
Gastroenterology/Hepatology
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 357 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 1764 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf