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- Bassil, A K, et al.
(författare)
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Little or no ability of obestatin to interact with ghrelin or modify motility in the rat gastrointestinal tract.
- 2007
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Ingår i: British Journal of Pharmacology. - : Wiley. - 0007-1188 .- 1476-5381. ; 150:1, s. 58-64
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Obestatin, encoded by the ghrelin gene may inhibit gastrointestinal (GI) motility. This activity was re-investigated.EXPERIMENTAL APPROACH: Rat GI motility was studied in vitro (jejunum contractility and cholinergically-mediated contractions of forestomach evoked by electrical field stimulation; EFS) and in vivo (gastric emptying and intestinal myoelectrical activity). Ghrelin receptor function was studied using a GTPgammaS assay and transfected cells.KEY RESULTS: Contractions of the jejunum or forestomach were unaffected by obestatin 100 nM or 0.01-1000 nM, respectively (P>0.05 each; n=4-18). Obestatin (0.1-1 nM) reduced the ability of ghrelin 1 microM to facilitate EFS-evoked contractions of the stomach (increases were 42.7+/-7.8% and 21.2+/-5.0 % in the absence and presence of obestatin 1 nM; P<0.05; n=12); higher concentrations (10-1000 nM) tended to reduce the response to ghrelin but changes were not statistically significant. Similar concentrations of obestatin did not significantly reduce a facilitation of contractions caused by the 5-HT(4) receptor agonist prucalopride, although an inhibitory trend occurred at the higher concentrations (increases were 69.3+/-14.0% and 42.6+/-8.7% in the absence and presence of 1000 nM obestatin; n=10). Obestatin (up to 10 microM) did not modulate recombinant ghrelin receptor function. Ghrelin increased gastric emptying and reduced MMC cycle time; obestatin (1000 and 30,000 pmol kg(-1) min(-1)) had no effects. Obestatin (2500 pmol kg(-1) min(-1), starting 10 min before ghrelin) did not prevent the ability of ghrelin (500 pmol kg(-1) min(-1)) to shorten MMC cycle time.CONCLUSIONS AND IMPLICATIONS: Obestatin has little ability to modulate rat GI motility.
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| 2. |
- Udeh-Momoh, CT, et al.
(författare)
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Protocol of the Cognitive Health in Ageing Register: Investigational, Observational and Trial Studies in Dementia Research (CHARIOT): Prospective Readiness cOhort (PRO) SubStudy
- 2021
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Ingår i: BMJ open. - : BMJ. - 2044-6055. ; 11:6, s. e043114-
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Tidskriftsartikel (refereegranskat)abstract
- The Cognitive Health in Ageing Register: Investigational, Observational and Trial Studies in Dementia Research (CHARIOT): Prospective Readiness cOhort (PRO) SubStudy (CPSS), sponsored by Janssen Pharmaceutical Research & Development LLC, is an Alzheimer’s disease (AD) biomarker enriched observational study that began 3 July 2015 CPSS aims to identify and validate determinants of AD, alongside cognitive, functional and biological changes in older adults with or without detectable evidence of AD pathology at baseline.Methods and analysisCPSS is a dual-site longitudinal cohort (3.5 years) assessed quarterly. Cognitively normal participants (60–85 years) were recruited across Greater London and Edinburgh. Participants are classified as high, medium (amnestic or non-amnestic) or low risk for developing mild cognitive impairment–Alzheimer’s disease based on their Repeatable Battery for the Assessment of Neuropsychological Status performance at screening. Additional AD-related assessments include: a novel cognitive composite, the Global Preclinical Alzheimer’s Cognitive Composite, brain MRI and positron emission tomography and cerebrospinal fluid analysis. Lifestyle, other cognitive and functional data, as well as biosamples (blood, urine, and saliva) are collected. Primarily, study analyses will evaluate longitudinal change in cognitive and functional outcomes. Annual interim analyses for descriptive data occur throughout the course of the study, although inferential statistics are conducted as required.Ethics and disseminationCPSS received ethical approvals from the London—Central Research Ethics Committee (15/LO/0711) and the Administration of Radioactive Substances Advisory Committee (RPC 630/3764/33110) The study is at the forefront of global AD prevention efforts, with frequent and robust sampling of the well-characterised cohort, allowing for detection of incipient pathophysiological, cognitive and functional changes that could inform therapeutic strategies to prevent and/or delay cognitive impairment and dementia. Dissemination of results will target the scientific community, research participants, volunteer community, public, industry, regulatory authorities and policymakers. On study completion, and following a predetermined embargo period, CPSS data are planned to be made accessible for analysis to facilitate further research into the determinants of AD pathology, onset of symptomatology and progression.Trial registration numberThe CHARIOT:PRO SubStudy is registered with clinicaltrials.gov (NCT02114372). Notices of protocol modifications will be made available through this trial registry.
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