Search results for "MOTILITY"
showing 10 items of 303 documents
Neurotensin: dual effect on the motor activity of rat duodenum
1992
The effects of neurotensin on mechanical activity of rat duodenum were investigated using an isometric-isovolumic preparation. Neurotensin (1 pM to 10 nM) induced a concentration-dependent, tetrodotoxin (TTX)-insensitive fall in both endoluminal pressure and isometric tension. At higher concentrations of neurotensin (1 nM to 1 microM) the relaxation was followed by a concentration-dependent TTX-insensitive contraction, detected only by an increase in endoluminal pressure. Different concentrations of neurotensin were required to desensitize the relaxant and the contractile actions of the neuropeptide. The relaxation was antagonized by apamin, while the contractile response was blocked by nif…
Spontaneous electromechanical activity in the rat duodenumin vitro
1990
Isolated rat duodenum shows spontaneous mechanical and electrical activities. Mechanical activity consists in changes both in endoluminal pressure and in isometric tension. Electrical activity is characterized by slow waves with superimposed bursts. This spontaneous activity is tetrodotoxin (TTX) resistant and therefore it is myogenic in origin. Indeed, TTX pretreatment, even in the presence of atropine and guanethidine, caused an increase in amplitude and in frequency of the electrical and mechanical activities. This finding indicates the presence of tonically active inhibitory intramural non adrenergic, non cholinergic (NANC) nerves. Duodenal longitudinal strips showed a spontaneous mecha…
Evaluation of esophageal motility and reflux in children treated for esophageal atresia with the use of combined multichannel intraluminal impedance …
2011
Abstract Background Gastroesophageal reflux (GER) and dysmotility are frequent in patients treated for esophageal atresia (EA). This aim of this study is to evaluate GER and dysmotility in young EA patients using pH–multichannel intraluminal impedance (pH-MII). Methods Fifteen patients with a mean age of 7.5 years (group 1) have been studied and compared with 15 children without congenital malformation, submitted to pH-MII for suspected GER (group 2). These latter patients serve as a control group of healthy subjects. The following impedance reflux and motility parameters have been studied on 10 standardized swallows: number of reflux episodes, mean acid clearing time, median bolus clearing…
Effects of calcium channel blockers on gastric emptying and acid secretion of the rat in vivo.
1986
Abstract Experiments were designed to evaluate the effects of three calcium channel blockers (verapamil, diltiazem and cinnarizine) on gastric emptying and secretion in the rat. Pretreatment with the calcium blockers delayed gastric emptying of phenol red in a dose-dependent manner. Verapamil was the most effective of the agents tested. Verapamil and diltiazem inhibited gastric acid secretion in the pylorus-ligated rat without affecting pepsin output. Cinnarizine was ineffective in this model. When the perfused lumen of the anaesthetized rat was used, verapamil was found to inhibit responses to carbachol or histamine more than those to pentagastrin. Further, we found a greater sensitivity t…
Enhancement of guinea-pig intestinal peristalsis by blockade of muscarinic M1-receptors
1988
1. The effects of pirenzepine and hyoscine on the peristaltic reflex were investigated in the guinea-pig isolated small intestine. Peristalsis was induced by raising the intraluminal pressure and the volume of fluid propelled was taken as a measure of the efficiency of peristaltic activity. 2. Low concentrations of pirenzepine (0.1-1 nM) and of hyoscine (0.01 nM) significantly enhanced peristalsis, whereas larger concentrations of both drugs caused inhibition. Pirenzepine was about 6 times less potent than hyoscine in increasing peristalsis, but was about 100 times less potent in inhibiting it. 3. Neither tolazoline (1 microM) nor naloxone (0.3 microM) affected the stimulatory action of pir…
Is there a relationship between the degree of preoperative motility impairment or the muscle thickness and the outcome of strabismus surgery in patie…
2005
There is considerable controversy regarding the performance of strabismus surgery in patients with Graves' orbitopathy (GO). The spectrum of recommendations extends from variable dose-effect correlations for these procedures (Esser, 1994; Mourits et al., 1990; Nguyen et al., 2002) to individualized approaches such as passive intraoperative motility testing and postoperative adjustment of sutures (Lueder et al., 1992; Nguyen et al., 2002), and to local anesthesia for intraoperative assessment of active motility (Kalpadakis et al., 2004). Furthermore, prior decompression surgery is known to contribute to an unpredictable outcome (Eckstein and Esser, 2003; Esser, 1994). We retrospectively anal…
Modulation by NO of acetylcholine release in the ileum of wild-type and NOS gene knockout mice.
2002
Nitric oxide (NO) inhibits the release of acetylcholine and cholinergic contractions in the small intestine of several species, but no information is available about the mouse ileum. This study examines the effects of NO on the electrically evoked release of [3H]acetylcholine and smooth muscle contraction in myenteric plexus-longitudinal muscle preparations of wild-type mice and of neuronal NO synthase (nNOS) and endothelial NOS (eNOS) knockout mice. The NOS inhibitor N G-nitro-l-arginine (l-NNA) and the guanylyl cyclase inhibitor 1 H-[1,2,4]oxadiazolo[4,3-α]quinoxalin-1-one (ODQ) concentration dependently increased the evoked [3H]acetylcholine release and cholinergic contractions in prepa…
Functional and neurochemical changes of the gastrointestinal tract in a rodent model of Parkinson's disease.
2009
Patients with Parkinson’s disease develop motor disturbances often accompanied by peripheral autonomic dysfunctions, including gastrointestinal disorders, such as dysphagia, gastric stasis and constipation. While the mechanisms subserving enteric autonomic dysfunctions are not clearly understood, they may involve the enteric dopaminergic and/or nitrergic systems. In the present study, we demonstrate that rats with unilateral 6-hydroxydopamine lesion of nigrostriatal dopaminergic neurons develop a marked inhibition of propulsive activity compared to sham-operated controls, as indicated by a 60% reduction of daily fecal output at the 4th week of observation. Immunohistochemical data revealed …
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 …