Search results for "intestinal motility"
showing 10 items of 76 documents
Inhibition of mechanical activity by neurotensin in rat proximal colon: involvement of nitric oxide.
1997
The aim of the present study was to define the nature of inhibitory action of neurotensin in rat proximal colon. Mechanical activity was detected as changes of intraluminal pressure. Neurotensin (10(-10) to 10(-7) M), in the presence of atropine (10(-6) M), guanethidine (10(-6) M), and nifedipine (10(-8) M), induced a tetrodotoxin-insensitive inhibitory effect characterized by the complete disappearance of the spontaneous phasic contractions. The inhibitory effect of neurotensin (10(-7) M) was abolished by scorpion venom (Leiurus quinquestriatus hebraeus) (10(-6) g/ml) or high K+ (40 mM KCl), whereas it persisted in the presence of omega-conotoxin GVIA, (10(-7) M). N omega-nitro-L-arginine…
Neuronostatin: peripheral site of action in mouse stomach.
2015
Neuronostatin is a 13-amino acid peptide encoded by somatostatin gene. It is distributed in different organs including gastrointestinal tract and has been involved in the control of food intake and gastroin-testinal motility, likely through an action in the brain. So far, there are no reports about the occurrence of peripheral action sites in the gut. Therefore, the purpose of the present study was to examine, in the mouse, the effects of peripheral administration of neuronostatin on food intake within 24 h and on gastrointestinal motility and to analyse neuronostatin actions on the gastric and intestinal mechanical activity in isolated preparations in vitro. When compared with PBS-treated …
Activation of angiotensin II type 1 receptors and contractile activity in human sigmoid colon in vitro.
2015
We propose and validate a non-invasive method that enables accurate detection of the discharge times of a relatively large number of motor units during excitatory and inhibitory reflex stimulations. HDsEMG and intramuscular EMG (iEMG) were recorded from the tibialis anterior muscle during ankle dorsiflexions performed at 5%, 10%, and 20% of the maximum voluntary contraction (MVC) force, in 9 healthy subjects. The tibial nerve (inhibitory reflex) and the peroneal nerve (excitatory reflex) were stimulated with constant current stimuli. In total, 416 motor units were identified from the automatic decomposition of the HDsEMG. The iEMG was decomposed using a state-of-the-art decomposition tool a…
Guanosine negatively modulates the gastric motor function in mouse
2013
The aim of the present study was to evaluate if guanine-based purines may affect the gastric motor function in mouse. Thus, the influence of guanosine on the gastric emptying rate in vivo was determined and its effects on spontaneous gastric mechanical activity, detected as changes of the intraluminal pressure, were analyzed in vitro before and after different treatments. Gastric gavage of guanosine (1.75-10 mg/kg) delayed the gastric emptying. Guanosine (30 μM-1 mM) induced a concentration-dependent relaxation of isolated stomach, which was not affected by the inhibition of the purine nucleoside phosphorylase enzyme by 4'-deaza-1'-aza-2'-deoxy-1'-(9-methylene)-immucillin-H. The inhibitory …
Involvement of prostaglandins and 5-hydroxytryptamine in the contractile effect of platelet-activating factor in rat isolated gastric corpus
1996
Abstract The present study characterizes the nature of the response to the platelet-activating factor (PAF) in isolated gastric corpus with and without mucosa. PAF (10-8 M) induced contraction of rat isolated gastric corpus strips followed by desensitization of this tissue. Incubation of strips with the specific PAF-receptor antagonist WEB 2086 (5 × 10-8 − 5 × 10-5 M), the prostaglandin blocker indomethacin (10-6 M) and the 5-hydroxytryptamine antagonist methysergide (10-5 M) reduced significantly the contraction induced by PAF. Neither of the histamine H1/H2 antagonists diphenhydramine (10-6 M) or cimetidine (10-5 M) affected the contraction induced by PAF. In contrast with the whole gastr…
Small bowel motility: relationship between smooth muscle contraction and electroenterogram signal.
2000
A study is made to correlate the electrical and mechanical activity of the smooth muscle of the small bowel. Bioelectrical signal recording from the intestinal serosa (electroenterogram) comprises a slow wave (SW) and spike burst (SB), though only the latter reflects intestinal pressure. The electroenterogram and smooth muscle pressure are simultaneously recorded in the canine small bowel. Spectral and time series analysis of the electroenterogram are performed to establish those electrical parameters that best reflect intestinal pressure. The results reveal an underlying correlation between the estimated parameters of electrical activity and smooth muscle pressure. In addition, parameters …
GABA and GABA receptors in the gastrointestinal tract: from motility to inflammation
2015
Although an extensive body of literature confirmed γ-aminobutyric acid (GABA) as mediator within the enteric nervous system (ENS) controlling gastrointestinal (GI) function, the true significance of GABAergic signalling in the gut is still a matter of debate. GABAergic cells in the bowel include neuronal and endocrine-like cells, suggesting GABA as modulator of both motor and secretory GI activity. GABA effects in the GI tract depend on the activation of ionotropic GABAA and GABAC receptors and metabotropic GABAB receptors, resulting in a potential noteworthy regulation of both the excitatory and inhibitory signalling in the ENS. However, the preservation of GABAergic signalling in the gut …
Effect of Marrubium globosum ssp libanoticum on intestinal motility
2007
In vivo methods for drug absorption - comparative physiologies, model selection, correlations with in vitro methods (IVIVC), and applications for for…
2013
This review summarizes the current knowledge on anatomy and physiology of the human gastrointestinal tract in comparison with that of common laboratory animals (dog, pig, rat and mouse) with emphasis on in vivo methods for testing and prediction of oral dosage form performance. A wide range of factors and methods are considered in addition, such as imaging methods, perfusion models, models for predicting segmental/regional absorption, in vitro in vivo correlations as well as models to investigate the effects of excipients and the role of food on drug absorption. One goal of the authors was to clearly identify the gaps in today's knowledge in order to stimulate further work on refining the e…