Motility of the large intestine and flow of digesta in pigs.

The motor function of the large intestine of pigs is incompletely understood. Here the ileo-caecal-colonic motility is investigated by means of chronically implanted extraluminal strain gauge transducers and simultaneous videofluoroscopy in six pigs. Motility parameters were evaluated by computer and manually.

Comparison of absorption of nutrients and secretion of water between oligomeric and polymeric enteral diets in pigs.

In patients who require enteric tube-feeding the osmolality of the formulas is assumed to play an important role. There is the dilemma that osmolality increases as the digestibility of formulas is enhanced by means of degradation of the nutrients. Hitherto there have been no reports of whether there are differences in nutrient absorption and water fluxes between iso-osmotic polymeric and hyperosmotic oligomeric diets.

Composition of enteral diets and meals providing optimal absorption rates of nutrients in mini pigs.

Background: Commercial enteral diets differ widely in nutrient composition. It is unknown whether the nutrient composition of the diets influences intestinal absorption.

Objective: The objective of this study was to investigate the effects of different enteral diets providing 60% of energy as carbohydrate, protein, or fat or 33.

The sodium concentration of enteral diets does not influence absorption of nutrients but induces intestinal secretion of water in miniature pigs.

Contradictory opinions exist as to whether the sodium concentration of enteral diets influences absorption of macronutrients and transepithelial movement of sodium and water. Therefore, we investigated the effects of various sodium concentrations of enteral diets on absorption of macronutrients and on net fluxes of sodium and water. In unanesthetized miniature pigs, a 150-cm jejunal segment was perfused with an oligopeptide (Peptisorb), an oligomeric and a polymeric diet.

Glucose and maltodextrin in enteral diets have different effects on jejunal absorption of nutrients, sodium and water and on flow rate in mini pigs.

In four mini pigs a segment of the proximal jejunum was temporarily isolated and perfused with two enteral diets containing isocaloric amounts either of glucose or maltodextrin. With regard to total energy, the diets were composed of 60% carbohydrate, 20% protein and 20% fat. The perfusion rates were 1, 2, 4, 6, and 8 kcal/min.

Absorption of nutrients is only slightly reduced by supplementing enteral formulas with viscous fiber in miniature pigs.

Viscous polysaccharides reduce intestinal absorption of glucose and diminish postprandial hyperglycemia. However, it is unknown whether viscous fiber also inhibits absorption of nutrients under conditions of enteric feeding. Therefore, we measured the absorption rates of nutrients in miniature pigs by perfusing a 150-cm length of jejunum with 8.

Intestinal absorption of nutrients is not influenced by soy fiber and does not differ between oligomeric and polymeric enteral diets.

Enteric feeding is often associated with diarrhea. To avoid this side effect, isoosmotic and fiber-supplemented enteral diets are recommended. The aims of this study were to determine whether supplementing enteral diets with soy fiber influences nutrient absorption and whether in enteric feeding absorption of nutrients and water fluxes differ between hyperosmotic oligomeric and isoosmotic polymeric diets.

Reserve capacities of the small intestine for absorption of energy.

Previous in vitro studies showed that the small intestine has reserve capacities for absorption of nutrients. However, the size of the reserve capacity is controversial. Therefore, we measured the intestinal capacity for absorption of energy in relation to the postprandial gastric delivery of energy into the gut.

Relationships between gastric emptying and intestinal absorption of nutrients and energy in mini pigs.

Little is known about the relationship between gastric emptying of nutrients regulated by feedback mechanisms and the absorptive capacity of the gut. Therefore, we wanted to elucidate these interrelationships. A 150-cm jejunal segment was perfused (1-8 kcal/min) with three different nutrient solutions (either 60% of energy as carbohydrate, or 60% as protein, or 33.

A model to investigate postoperative ileus with strain gauge transducers in awake rats.

Background: Postoperative ileus influences patients well-being, hospital stay, and health cost, and postoperative inhibition of colonic motility is a major contributor to postoperative ileus. Experimental models for investigating postoperative ileus are needed. In particular, recording of postoperative colonic motility in awake rats has not been described yet.

Effects of somatostatin on luminal transit and absorption of nutrients in the proximal gut of minipigs.

A discrepancy exists on the effects of somatostatin on the absorption of nutrients: in humans, absorption was found to be reduced, whereas in rats no effects were observed. However, intestinal absorption might be influenced by the transit rate of contents. This was not considered in previous studies.

Effects of enteral feedback inhibition on motility, luminal flow, and absorption of nutrients in proximal gut of minipigs.

We wanted to clarify whether the postprandial intestinal feedback control activated by nutrients in the distal gut exerts different effects on motility, transit of digesta, and absorption of nutrients in the proximal gut. Additionally, interrelationships among motility, transit, and absorption were to be elucidated because these relationships have only been investigated in the fasted state. In five minipigs, a 150-cm segment of the proximal jejunum was isolated by two cannulas.

Effects of enteral infusion of hypertonic saline and nutrients on canine jejunal motor patterns.

The aim of the study was to clarify the effects of hypertonic solutions on jejunal motility. The study focused on differential effects of hypertonic saline and nutrients. Motility of the canine proximal jejunum was recorded with closely spaced strain-gauge transducers.

5-Hydroxytryptophan modulates postprandial motor patterns of canine proximal small intestine.

The aim of the study was to clarify whether 5-hydroxytryptophan (5-HTP) stimulates the postprandial motor pattern of the duodenum in a similar way as that of the adjacent jejunal segment in dogs. Computerized analysis of motor patterns recorded by closely spaced strain gauges focused on the temporal and spatial distribution of the contractions. Results indicate that 5-HTP increased the incidence and the length of the spread of contraction waves after both an acaloric and a nutrient meal in the duodenum as well as in the adjacent jejunal segment.

Effects of ileal infusions of nutrients on motor patterns of canine small intestine.

In the present study, effects of ileal infusions of nutrients on motor patterns of the proximal small intestine and on gastric emptying were investigated in dogs. An acaloric meal was administered orally, and equicaloric loads of amino acids, oleate, and glucose were infused into the ileum at different doses (0.3, 0.

Propagation velocities and frequencies of contractions along canine small intestine.

This study was performed to clarify in detail the behavior of the propagation velocities and frequencies of contractions along the canine small intestine. In conscious dogs, duodenal, jejunal, and ileal contractions were recorded by multiple, closely spaced strain gauges and analyzed by a computerized method. During both the interdigestive and postprandial states, the propagation velocity increased from the duodenal bulb to the distal duodenum and declined aborally within the jejunum, reaching rather constant values in the ileum.

Effects of neurotensin on motor patterns of canine duodenum and proximal jejunum.

The aim of this study was to clarify if small doses of neurotensin (2.5 and 5.0 pmol.

Characteristics of postprandial duodenal motor patterns in dogs.

In this study special attention was paid to the characteristics of duodenal motility under the influence of various test meals. Closely spaced strain gauge transducers and a computerized method were used to analyze motor patterns of the duodenum and the adjacent jejunum. Compared with an acaloric meal, nutrients shortened the length of contraction spread in the duodenum from 5.

Effects of various agents on ileal postprandial motor patterns and transit of chyme in dogs.

Effects of intravenous infusions of somatostatin, methionine-enkephalin, and 5-hydroxytryptophan on canine ileal motor patterns and transit of chyme were investigated postprandially. Motility was recorded by multiple closely spaced extraluminal strain gauges. By a computerized method, the length of contraction spread and other motility parameters were evaluated.

Neurotensin changes the motor pattern in canine ileum from propulsive to segmenting.

Modulation of ileal propulsive motility by different doses of neurotensin has been determined in detail. In conscious dogs neurotensin (2.5, 5, and 10 pmol/kg/min) was intravenously infused during the propulsive motor pattern induced by an acaloric viscous meal.

Computer analysis of orally propagated contractions in canine small intestine after Billroth-II gastrectomy.

The aims of the study were to characterize an unusual motor pattern with orally propagated intestinal contractions occurring after subtotal gastrectomy and to clarify if orally propagated contractions also occur during the normal fasted and fed motor pattern in intact dogs. Jejunal motility was recorded with multiple closely spaced extraluminal transducers. Contractile patterns were analyzed by a special computerized method.

Gastrointestinal motility and gastric emptying after Billroth II gastrectomy in dogs.

This study was undertaken to compare the effects of subtotal Billroth II gastrectomy on gastric emptying and gastrointestinal motility with previously published results in intact dogs and in dogs with subtotal Roux-Y gastrectomy. Extraluminal strain gauge transducers were used to study gastrointestinal motility after Billroth II gastrectomy in four conscious dogs. Gastric emptying was measured radiographically.

Canine motility and gastric emptying after subtotal gastrectomy.

The aim of the present study was to elucidate factors influencing gastric emptying in dogs after a two-thirds distal gastrectomy with either Roux-Y or Billroth I reconstruction. The effects of a medium-viscosity nutrient meal on gastrointestinal motility and gastric emptying were investigated. Motility was recorded with long-term implanted extraluminal strain gauge force transducers; gastric emptying was measured radiographically.

Effects of nutrients on gastrointestinal motility and gastric emptying after Billroth-I gastrectomy in dogs.

We wanted to clarify the way in which nutrients influence gastrointestinal motility and gastric emptying following distal gastrectomy with Billroth-I gastroduodenostomy. Four gastrectomized dogs were equipped with extraluminal strain gauge transducers. Gastric emptying was measured radiographically.

Motility of the pyloric sphincter studied by the inductograph method in conscious dogs.

The aim of the study is to evaluate the motility of the pyloric sphincter in conscious dogs by means of extraluminal transducers. For this purpose induction coils were chronically implanted in 12 dogs. After a meal the pylorus opened and closed in relation to the gastric waves.