Gastric and duodenal motility in the cat: the role of central innervation assessed by transient vagal blockade

1986 ◽  
Vol 64 (6) ◽  
pp. 712-716 ◽  
Author(s):  
M. P. Bendeck ◽  
R. P. E. Reynolds
Keyword(s):  
Small Bowel ◽  
Contractile Activity ◽  
General Pattern ◽  
The Body ◽  
Complex Activity ◽  
Duodenal Motility ◽  
Vagal Blockade ◽  
Proximal Small Bowel ◽  
Vagal Innervation

Experiments were performed on four cats to characterize fasting gastric and small bowel motility and to assess the role of extrinsic vagal innervation in the control of that motor activity. A multilumen manometry tube was positioned to record pressure changes from the proximal small bowel and stomach. Transient vagal nerve blockade was accomplished by cooling the cervical vagosympathetic nerve trunks, previously isolated in skin loops on each side of the neck. Two characteristic patterns of basal activity were documented in the stomach: (i) regular phasic contractions of variable amplitude in the body of the stomach; and (ii) infrequent, irregular contractions of high amplitude in the distal antrum. In the duodenum, two predominant activity patterns were noted: (i) periods of continuous irregular activity; and (ii) irregular clusters of contractions separated by quiescent intervals. No typical migrating motor complex activity was seen in the basal gastric or small bowel recordings. Bilateral vagal blockade did not consistently change the general pattern of gastric or small bowel activity, but did appear to reduce gastric contractile activity, as measured by motility indices. We conclude that extrinsic vagal innervation does not play a major role in the control of fasting feline gastric and duodenal motility.

Small intestinal motility in fasted and postprandial states: effect of transient vagosympathetic blockade

1987 ◽  
Vol 252 (3) ◽  
pp. G301-G308 ◽  
Author(s):  
S. A. Chung ◽  
N. E. Diamant
Keyword(s):  
Small Bowel ◽  
Intestinal Motility ◽  
Gastric Fundus ◽  
Phase Iii ◽  
Entire Small Bowel ◽  
Vagal Blockade ◽  
Small Intestinal Motility ◽  
Proximal Small Bowel ◽  
Small Intestinal ◽  
Gastric Contractions

We investigated vagal control of the migrating myoelectric complex (MMC) and postprandial pattern of the canine small intestine. Gastric and small intestinal motility were monitored in six conscious dogs. The vagosympathetic nerves, previously isolated in bilateral skin loops, were blocked by cooling. To feed, a meat-based liquid food was infused by tube into the gastric fundus. MMC phases I, II, III, and IV were observed in the fasted state. On feeding, the fed pattern appeared quickly in the proximal small bowel but was delayed distally. Vagal blockade abolished all gastric contractions and spiking activity as well as the small bowel fed pattern. During vagal blockade, the small bowel exhibited MMC-like migrating bursts of spikes in both the fasted and fed states. The migration and cycling of these bursts were not significantly different from the MMC, but the duodenal and jejunal phase II was absent or shortened. On termination of vagal blockade, normal fasting or fed activity reappeared but with a delay in the fed pattern distally. We conclude: the ileum is the least sensitive to vagal blockade; the fasting vagal influence is exerted primarily on phases I and II of the duodenal and jejunal MMC; the fed pattern throughout the entire small bowel is normally dependent upon vagal integrity; the phase III-like bursts of activity seen during vagal blockade likely represents the intrinsic small bowel MMC, which is vagally independent.

Jejunal regulation of gastric motility patterns: effect of extrinsic neural continuity to stomach

1990 ◽  
Vol 258 (1) ◽  
pp. G32-G37 ◽  
Author(s):  
M. P. Spencer ◽  
M. G. Sarr ◽  
N. J. Soper ◽  
N. S. Hakim
Keyword(s):  
Small Intestine ◽  
Gastric Motility ◽  
Contractile Activity ◽  
Inhibitory Effects ◽  
Extrinsic Denervation ◽  
Recovery Stage ◽  
Neural Input ◽  
Vagal Innervation ◽  
Stage 1

This study was designed to determine the role of extrinsic gastric innervation in mediating the inhibitory effects of jejunal infusion of mixed nutrients on canine interdigestive gastric motility patterns. Four dogs underwent transection of all extrinsic and intrinsic neural continuity to the stomach except for careful preservation of vagal innervation (stage 1). Antral manometry catheters, antral electrodes, intestinal electrodes, and a jejunal infusion catheter were placed. After a 2-wk recovery, stage 1 studies of myoelectric and contractile activity of the stomach and small bowel during fasting were recorded on four occasions during infusion of isomolar solutions of either nonnutrient NaCl (150 mM) or mixed nutrients (50% Meritene solution) into the jejunum at 2.9 ml/min for 6 h. Identical studies (stage 2) were repeated after completion of extrinsic denervation of the stomach by supradiaphragmatic vagotomy. In stage 1 studies, jejunal nutrients (83 kcal/h) inhibited the characteristic interdigestive cyclic motility patterns in the stomach and duodenum for greater than or equal to 172 min during jejunal infusion of mixed nutrients. After completion of extrinsic denervation (stage 2), jejunal infusion of nutrients had the same effects with inhibition of cyclic motility patterns in the stomach and small intestine. We concluded that inhibition of interdigestive gastric motility patterns by jejunally infused nutrients is mediated by hormonal mechanisms and not by nonvagal or vagal extrinsic neural input to the stomach.

Role of vagus nerve in postprandial antropyloric coordination in conscious dogs

2005 ◽  
Vol 288 (3) ◽  
pp. G487-G495 ◽  
Author(s):  
Tomio Ueno ◽  
Kenichiro Uemura ◽  
Mary B. Harris ◽  
Theodore N. Pappas ◽  
Toku Takahashi
Keyword(s):  
Gastric Emptying ◽  
Vagus Nerve ◽  
Late Phase ◽  
Motor Pattern ◽  
The Body ◽  
Conscious Dogs ◽  
Solid Meal ◽  
Liquid Meal ◽  
Vagal Blockade

It is generally believed that gastric emptying of solids is regulated by a coordinated motor pattern between the antrum and pylorus. We studied the role of the vagus nerve in mediating postprandial coordination between the antrum and pylorus. Force transducers were implanted on the serosal surface of the body, antrum, pylorus, and duodenum in seven dogs. Dogs were given either a solid or a liquid meal, and gastroduodenal motility was recorded over 10 h. Gastric emptying was evaluated with radiopaque markers mixed with a solid meal. Dogs were treated with hexamethonium, NG-nitro-l-arginine methyl ester (l-NAME), or transient vagal nerve blockade by cooling. A postprandial motility pattern showed three distinct phases: early, intermediate, and late. In the late phase, profound pyloric relaxations predominantly synchronized with giant antral contractions that were defined as postprandial antropyloric coordination. A gastric emptying study revealed that the time at which gastric contents entered into the duodenum occurred concomitantly with antropyloric coordination. Treatment by vagal blockade or hexamethonium significantly reduced postprandial antral contractions and pyloric relaxations of the late phase. l-NAME changed pyloric motor patterns from relaxation dominant to contraction dominant. Solid gastric emptying was significantly attenuated by treatment with hexamethonium, l-NAME, and vagal blockade. Postprandial antropyloric coordination was not seen after feeding a liquid meal. It is concluded that postprandial antropyloric coordination plays an important role to regulate gastric emptying of a solid food. Postprandial antropyloric coordination is regulated by the vagus nerve and nitrergic neurons in conscious dogs.

Oesophageal peristalsis in the cat: the role of central innervation assessed by transient vagal blockade

1985 ◽  
Vol 63 (2) ◽  
pp. 122-130 ◽  
Author(s):  
R. P. E. Reynolds ◽  
T. Y. El-Sharkawy ◽  
N. E. Diamant
Keyword(s):  
Smooth Muscle ◽  
Striated Muscle ◽  
Vagal Nerve ◽  
The Body ◽  
Nerve Blockade ◽  
Primary Peristalsis ◽  
Vagal Blockade ◽  
Central Innervation ◽  
Secondary Peristalsis

Studies were performed on five cats to assess the role of extrinsic vagal innervation in the control of peristalsis in the smooth muscle oesophagus. Transient vagal nerve blockade was accomplished by cooling the cervical vagosympathetic nerve trunks previously isolated in skin loops on each side of the neck. Peristalsis throughout the body of the oesophagus was monitored using a continuously perfused multilumen manometry tube. Striated and smooth muscle portions of the esophagus were delineated by abolishing smooth muscle activity with atropine. Secondary peristalsis was assessed by intra-oesophageal balloon distension studies. The threshold volume for balloon-induced secondary peristalsis was lower in the smooth muscle oesophagus. Unilateral vagal blockade reduced the incidence of primary and secondary peristalsis in the striated muscle oesophagus but not in the smooth muscle oesophagus. Bilateral vagal nerve blockade abolished primary swallow-induced peristalsis and secondary peristalsis in both the smooth and striated muscle cat oesophagus. Administration of cholinergic agents or adrenergic blocking agents failed to restore secondary peristalsis in the smooth muscle oesophagus during vagal cooling. We conclude that connections to the central nervous system via the vagal nerve trunks are required for normal secondary as well as primary peristalsis in both the smooth and striated muscle portions of the cat oesophagus.

scholarly journals Modelling the effects of short and random proto-neural elongations

2017 ◽  
Vol 14 (135) ◽  
pp. 20170399 ◽  
Author(s):  
Oltman O. de Wiljes ◽  
R. A. J. van Elburg ◽  
Fred A. Keijzer
Keyword(s):  
Computational Study ◽  
Contractile Activity ◽  
Small Body ◽  
Scale Up ◽  
The Body ◽  
Central Component ◽  
Proof Of Concept ◽  
Nervous Systems ◽  
Evolutionary Route

To understand how neurons and nervous systems first evolved, we need an account of the origins of neural elongations: why did neural elongations (axons and dendrites) first originate, such that they could become the central component of both neurons and nervous systems? Two contrasting conceptual accounts provide different answers to this question. Braitenberg's vehicles provide the iconic illustration of the dominant input–output (IO) view. Here, the basic role of neural elongations is to connect sensors to effectors, both situated at different positions within the body. For this function, neural elongations are thought of as comparatively long and specific connections, which require an articulated body involving substantial developmental processes to build. Internal coordination (IC) models stress a different function for early nervous systems. Here, the coordination of activity across extended parts of a multicellular body is held central, in particular, for the contractions of (muscle) tissue. An IC perspective allows the hypothesis that the earliest proto-neural elongations could have been functional even when they were initially simple, short and random connections, as long as they enhanced the patterning of contractile activity across a multicellular surface. The present computational study provides a proof of concept that such short and random neural elongations can play this role. While an excitable epithelium can generate basic forms of patterning for small body configurations, adding elongations allows such patterning to scale up to larger bodies. This result supports a new, more gradual evolutionary route towards the origins of the very first neurons and nervous systems.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

The Role of Computer Modeling in Electrocardiography

1990 ◽  
Vol 29 (04) ◽  
pp. 282-288 ◽  
Author(s):  
A. van Oosterom
Keyword(s):  
Electrical Activity ◽  
Computer Modeling ◽  
Body Surface ◽  
Electrical Current ◽  
The Body ◽  
Volume Conductor ◽  
Current Generator ◽  
Cardiac Electrical Activity ◽  
Source Models

AbstractThis paper introduces some levels at which the computer has been incorporated in the research into the basis of electrocardiography. The emphasis lies on the modeling of the heart as an electrical current generator and of the properties of the body as a volume conductor, both playing a major role in the shaping of the electrocardiographic waveforms recorded at the body surface. It is claimed that the Forward-Problem of electrocardiography is no longer a problem. Several source models of cardiac electrical activity are considered, one of which can be directly interpreted in terms of the underlying electrophysiology (the depolarization sequence of the ventricles). The importance of using tailored rather than textbook geometry in inverse procedures is stressed.

Role of MRI in the diagnosis of small bowel diseases

2005 ◽  
Vol 43 (05) ◽  
Author(s):  
M Babos ◽  
A Palkó ◽  
L Kardos ◽  
I Kiss ◽  
F Nagy
Keyword(s):  
Small Bowel ◽  
Bowel Diseases ◽  
Small Bowel Diseases

Questions on the role of biofilms for the adaptation of microorganisms to unfavorable environmental factors by the example of P. aeruginosa

2020 ◽  
Vol 99 (4) ◽  
pp. 379-383
Author(s):  
Vasily N. Afonyushkin ◽  
N. A. Donchenko ◽  
Ju. N. Kozlova ◽  
N. A. Davidova ◽  
V. Yu. Koptev ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Environmental Factors ◽  
Barrier Function ◽  
Infectious Agent ◽  
Antagonistic Activity ◽  
The Body ◽  
Main Function ◽  
Pathogenic Potential ◽  
The Face

Pseudomonas aeruginosa is a widely represented species of bacteria possessing of a pathogenic potential. This infectious agent is causing wound infections, fibrotic cystitis, fibrosing pneumonia, bacterial sepsis, etc. The microorganism is highly resistant to antiseptics, disinfectants, immune system responses of the body. The responses of a quorum sense of this kind of bacteria ensure the inclusion of many pathogenicity factors. The analysis of the scientific literature made it possible to formulate four questions concerning the role of biofilms for the adaptation of P. aeruginosa to adverse environmental factors: Is another person appears to be predominantly of a source an etiological agent or the source of P. aeruginosa infection in the environment? Does the formation of biofilms influence on the antibiotic resistance? How the antagonistic activity of microorganisms is realized in biofilm form? What is the main function of biofilms in the functioning of bacteria? A hypothesis has been put forward the effect of biofilms on the increase of antibiotic resistance of bacteria and, in particular, P. aeruginosa to be secondary in charcter. It is more likely a biofilmboth to fulfill the function of storing nutrients and provide topical competition in the face of food scarcity. In connection with the incompatibility of the molecular radii of most antibiotics and pores in biofilm, biofilm is doubtful to be capable of performing a barrier function for protecting against antibiotics. However, with respect to antibodies and immunocompetent cells, the barrier function is beyond doubt. The biofilm is more likely to fulfill the function of storing nutrients and providing topical competition in conditions of scarcity of food resources.

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