Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society
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Neurogastroenterol. Motil. · Jul 2011
Randomized Controlled TrialCharacterization of a reproducible gastric pain model using oral capsaicin titration in healthy volunteers.
Sensory sensitization is one of the main pathophysiological hypotheses in functional gastrointestinal disorders (FGIDs). As sensitization may affect various sensory modalities, we aimed to develop a reproducible gastric pain model utilizing polymodal pathways for use in functional and other pain disorders. ⋯ Standardized gastric pain can be conveniently achieved in a majority of healthy subjects using a simple oral capsaicin titration, with minimal adverse events. The between-test reproducibility is high and nocebo responses are negligible. This technique stimulating a multimodal physiological pathway will be useful in the investigation of sensory changes in FGIDs, including functional dyspepsia.
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Neurogastroenterol. Motil. · Jul 2011
Clinical TrialfMRI and MEG analysis of visceral pain in healthy volunteers.
Although many studies of painful rectal stimulation have found activation in the insula, cingulate, somatosensory, prefrontal cortices and thalamus, there is considerable variability when comparing functional magnetic resonance imaging (fMRI) results. Multiple factors may be responsible, including the model used in fMRI data analysis. Here, we assess the temporal response of activity to rectal barostat distension using novel fMRI and magnetoencephalography (MEG) analysis. ⋯ In studies of visceral pain, fMRI model design strongly influences the detected activity and must be accounted for to effectively explore the fMRI data in healthy subjects and within patient groups. In particular a strong cortical response is detected to inflation and deflation of the barostat, rather than to its absolute volume.
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Neurogastroenterol. Motil. · Jul 2011
Role of neuronal nitric oxide synthase in colonic distension-induced hyperalgesia in distal colon of neonatal maternal separated male rats.
Nitric oxide (NO) is implicated in the pathogenesis of irritable bowel syndrome (IBS) but the underlying mechanism is unclear. Thus, the aim of the present study is to examine the role of NO synthase (NOS) expression in the distal colon of neonatal maternal separation (NMS) model rats employed in IBS studies. ⋯ Neonatal maternal separation increased the NO generation by nNOS upregulation that interact with reactive oxygen species contributing to the visceral hypersensitivity in IBS.
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Neurogastroenterol. Motil. · Jul 2011
Entacapone promotes cAMP-dependent colonic Cl(-) secretion in rats.
Entacapone is a promising drug used widely for the treatment of Parkinson's disease (PD) as a catechol-O-methyl transferase (COMT) inhibitor. However, entacapone has gastrointestinal side effects. The aim of this study was to investigate the effects of entacapone on the epithelial ion transport in rat distal colon, and explore the underlying mechanism. ⋯ Entacapone stimulates cAMP-dependent Cl(-) secretion in the rat colon, and this process is regulated by endogenous PG and the submucosal enteric nervous system.
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Neurogastroenterol. Motil. · Jul 2011
Neonatal cystitis-induced colonic hypersensitivity in adult rats: a model of viscero-visceral convergence.
The objective of this study was to determine if neonatal cystitis alters colonic sensitivity later in life and to investigate the role of peripheral mechanisms. ⋯ Neonatal cystitis results in colonic hypersensitivity in adult rats without changing tissue histology or the mechanosensitive properties of CRD-sensitive PNAs. Neonatal cystitis does result in overexpression of spinal NR1 subunit in adult rats.