Computerised method for pattern recognition of intestinal motility: functional significance of the spread of contractions.
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Animals↗
Biomedical subjects
H J Ehrlein
Publications and source records attributed to H J Ehrlein.
Pharmacology of a gut motility stimulating enkephalin analogue.
The enkephalin analogue pentapeptide Hoe 825 (Tyr-D-Lys-Gly-Phe-L-homocysteine-thiolactone) is a mixed mu/delta opiate agonist. The peptide stimulated interdigestive gut motility at all parts of the intestine in conscious and anaesthetized animals. In dogs digestive motility, measuring mechanical activity, was stimulated with respect to segmental and propulsive properties. The canine uterus was sensitive to the enkephalin. Hoe 825 acts by i.v. or s.c. application, whereas the latter increases the duration of action significantly. The compound's effect can be blocked by naloxone indicating a receptor mediated action, which is localised peripherally. The compound is devoid of a dependence risk, because it does not penetrate into the CNS. At therapeutic doses (in the dog 0.5-2 micrograms/kg i.v.) the compound does not affect cardiovascular, renal or endocrine functions and was without effect on serum blood glucose levels in rats and rabbits.
Action Potentials↗
Mechanical factors regulating gastric emptying of viscous nutrient meals in dogs.
The aim of this study was to determine the mechanisms controlling gastric emptying of viscous meals. In four conscious dogs the antral, pyloric and duodenal activities were recorded with strain-gauge transducers and induction coils during gastric evacuation of an inert cellulose meal and of four nutrient meals containing mannitol, casein, glucose or oleic acid. Gastric emptying and the internal pyloric and duodenal diameters were measured from radiographs. The nutrients delayed gastric emptying and diminished to a various extent the antral and duodenal motility as well as the pyloric opening. The motility gradient between antral and duodenal activity showed no relationship to the emptying delay. The duodenal lumen was reduced and the propulsive contractions of the duodenum decreased while the segmental activity increased. The findings suggest that gastric emptying is controlled by (1) the depth of the antral waves, (2) the pyloric opening, (3) the receptive relaxation of the duodenum and (4) the type of the duodenal contractions. By contrast the sequence of the terminal antral contraction and the pyloric closure, as well as the co-ordination between pyloric and duodenal contractions, played no important role in regulating gastric emptying.
Animals↗
Phase relationship of the circadian rhythms of feed intake, caecal motility and production of soft and hard faeces in domestic rabbits.
In rabbits kept under 12:12 h light conditions, caecal contractions were recorded by implanted strain gauges or induction coils. In animals fed ad libitum caecal contraction frequency varied cyclically in phase with the circadian rhythm of feed intake. Both had their minimum during the time of soft faeces production. Thus all 3 functions seem to depend on the same circadian clock. The close link between caecotrophy and caecal contractions can, however, be upset by either time-restricted feeding or by fasting.
Animals↗
Effects of 5-hydroxytryptophane and insulin on gastric motility and emptying in dogs.
In unanaesthetized dogs gastroduodenal motility was investigated by simultaneous transducer recordings and fluoroscopy; gastric emptying was measured via a duodenal cannula. Intravenous infusion of 5-hydroxytryptophane enhanced both gastric emptying and antral and duodenal motility. The intravenous injection of insulin was followed by an initial inhibition of antral and duodenal motility and of gastric emptying. In a second phase antral and duodenal contractions were augmented, while the proximal stomach relaxed. Thereby, gastric emptying increased only slightly in spite of the strong antral activity. It is concluded that several factors are involved in controlling gastric emptying.
5-Hydroxytryptophan↗
Effect of oleic acid on canine gastroduodenal motility, pyloric diameter and gastric emptying.
The motility of the antrum, duodenum and pylorus was recorded with strain gauge transducers and induction coils in conscious beagle dogs. The effect of oleic acid on gastroduodenal motility and on the pyloric diameter was studied in the interdigestive state and during emptying of a mashed potato meal. The flow of digesta was observed fluoroscopically. Gastric emptying was measured by planimetry of the radiopaque gastric silhouette. The intraduodenal injection of oleic acid reduced the diameter of the pylorus in the empty stomach. In the digestive state oleic acid diminished gastric emptying of the potato meal. The antral motility was significantly diminished (amplitudes from 100 +/- 39.2 to 93 +/- 41.2 mV, contractile frequency from 4.3 +/- 0.6 to 3.8 +/- 1.5 min-1, motility index from 435 +/- 197 to 345 +/- 213 V, n = 3400-4700 contractions), whereas the duodenal motility was enhanced (amplitudes from 100 +/- 49.6 to 106 +/- 58.6 mV, motility index from 548 +/- 296 to 567 +/- 377 V, n = 5800-6400 contractions). The diameter of the pyloric opening during the phase of relaxation was about 25% less in comparison to the control meal. The weaker antral contractions and the less opening of the pylorus diminished gastric evacuation and enhanced retropulsion of the gastric chyme. A higher incidence of segmental duodenal contractions produced a slower transfer of digesta. Results demonstrated that gastric emptying was regulated by several co-operating factors. The pylorus was involved by producing different resistances to flow during its phase of relaxation.
Animals↗
Colonic motility and transit of digesta during hard and soft faeces formation in rabbits.
Rabbits produce hard and soft faeces in a circadian rhythm. This study was undertaken in order to examine the motor function of the colon in relation to the formation of these two types of faeces. Colonic motility was measured in unanaesthetized rabbits using strain-gauge transducers and simultaneous radiography. Three types of contractions were found in the rabbit proximal colon: haustral activity, segmental activity, and mass peristalsis. Distinctly different motor patterns were observed during the formation of hard and soft faeces. When hard faeces were produced, the motor activity of the proximal colon was enhanced. It consisted of segmental and haustral activity. The segmental contractions separated the digesta into faecal pellets and forced them slowly aborad, whereas the movements of the haustra carried the liquid contents back towards the caecum. When soft faeces were produced haustral and segmental activity was reduced and transfer of the digesta through the proximal colon was accelerated by mass movements. In contrast to the proximal colon, the motility of the distal colon was enhanced during the formation of soft faeces and decreased during the production of hard faeces. The results support the concept that hard faeces are chiefly produced by a separation of liquids and solids and by a retrograde transfer of liquid digesta rather than by an increased absorption of water.
Animals↗
Computer analysis of mechanical activity of gastroduodenal junction in unanaesthetized dogs.
In four conscious dogs mechanical activity of the gastroduodenal junction was recorded with chronically implanted strain gauge transducers and induction coils. The data were evaluated by a computer. Analog circuits were used in order to reduce the data which were transferred to the computer. In the digestive state the contractions of the pyloric sphincter and duodenal bulb were correlated in such a way that the contractions of the duodenal bulb were inhibited when the gastric waves travelled across the antrum and that the bulb contracted once or twice when the peristaltic waves arrived at the gastroduodenal junction. However, the timing between pyloric and duodenal contractions was imperfect. Contraction maxima of the duodenal bulb often occurred before the pylorus was closed. This was due to the different inherent frequencies of the pyloric and duodenal contractions. In the interdigestive state the timing between the pyloric and duodenal contractions was as imperfect as during the digestive state. In phase III of the interdigestive activity, however, the strong antral contractions were regularly associated with inhibition of the duodenal bulb. This phenomenon can be interpreted as co-ordination between gastric and duodenal activity.
Animals↗
Physiological significance of the contractions of the rabbit proximal colon.
In humans and in carnivores the motor activity of the colon was separated into various types based on records of the intraluminal pressure. However, little is actually known about the physiological significance of the various pressure waves. The aim of the present investigation was to clarify the basic pattern of colonic motility in a herbivorous species. Motility of the proximal colon was studied by strain gauge transducer records combined either with fluoroscopy or by direct visual observation in conscious and anaesthetized rabbits. In the proximal colon three types of contraction were found: (1) high frequency repetitive contractions, (2) low frequency rises of the base line, and (3) monophasic progressive waves. The frequency of the repetitive contractions was 13.8 contractions/min at the oral site and 16.3 contractions/min at the aboral site of the proximal colon. The mean duration of the repetitive contractions was 3.2 +/- 1 s. They coincided with orally migrating (1-2 mm/s) shallow annular constrictions which represented haustral activity. The low frequency rises of the base line (mean duration 13 +/- 47 s) were associated with aborally migrating (7 mm/min) deep annular constrictions representing segmental activity. The monophasic progressive waves represented peristaltic contractions. The mean durations of the monophasic waves 5.5 +/- 1.2 s (period of hard faeces formation), and 9.7 +/- 2.8 s (period of soft faeces formation), the average rates of progression were 3.2 +/- 1.2 cm/s (period of hard faeces production), and 1.3 +/- 0.6 cm/s (period of soft faeces production). The results proved that the colonic motility of rabbits consisted of a complex motor pattern. The present classification was similar but not identical with that described in carnivores and man. Further comparative studies on other mammals are necessary to decide whether the motor activity of the colon is comparable between various species.
Animals↗
Effect of viscosity of test meals on gastric emptying in dogs.
In five dogs gastric emptying of low, medium and high viscosity meals was measured via a duodenal cannula. The rate of emptying depended on the viscosity of the test meals: the time for half emptying was 4.5 +/- 2.2 min with the low viscosity liquid meal (1 centipoise), 28.9 +/- 9.5 min with the test meal of medium viscosity (10(5) centipoise), and 43 +/- 11.8 min with the test meal of high viscosity (10(6) centipoise). The emptying curves of the medium and high viscosity meals were sigmoid, whereas the curve representing the emptying of the low viscosity liquid meal followed an exponential pattern. Results indicate that the viscosity of the meal is an important factor for the rate of gastric emptying.
Animal Feed↗
Motor function of gastric antrum and pylorus for evacuation of low and high viscosity meals in dogs.
In five conscious dogs motility of the antrum, pyloric sphincter, and duodenum was recorded with strain gauge transducers and induction coils. Gastric evacuation of low, medium, and high viscosity meals was measured via a duodenal cannula and observed simultaneously by radiography. Computer analysis of the propagation of the gastric waves revealed increased velocity in the distal antrum but no simultaneous contractions of the terminal antrum and pyloric sphincter. Radiography showed, and measurements of the antral diameter confirmed, that the indentations of the gastric waves were significantly deeper with the low viscosity liquid meal compared with the medium and high viscosity meals. Thereby, retropulsion of the medium and high viscosity ingesta was produced. Results indicated that gastric evacuation was regulated predominantly by the depth of the peristaltic indentation, which depended on the viscosity of the gastric contents. Nothing indicated that the phasic contractions of the pyloric sphincter were of importance for the regulation of gastric emptying.
Animals↗
The utility of cellulose meals for studies on gastrointestinal motility in dogs.
This study evaluated the effect of a cellulose meal and a cellulose-oleic acid meal on gastroduodenal motility and gastric emptying. The cellulose meal produced a high antral motility index (100 +/- 34 V/10 min) and a high proportion (80.2%) of propulsive duodenal contractions. The oleic acid meal was associated with a significantly lower antral motility index (70 +/- 34 V/10 min), a high proportion (78.7%) of segmental duodenal contractions, and a reduced emptying rate (half time 93 +/- 18 versus 30 +/- 7 min). Results indicate that the inert cellulose meal is advantageous in studying the effects of different nutrients on gastrointestinal motility.
Animals↗
[Stomach motility in the rabbit].
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Animals↗
Silage intake, rumination and pseudo-rumination activity in sheep studied by radiography and jaw movement recordings.
1. The eating and ruminating activity of four rams given long-chopped silage ad lib. in two daily meals was studied by jaw movement recordings. The events of rumination and pseudo-rumination were observed by fluoroscopy and by cineradiography. 2. The rate of eating was highest at the beginning of the main meal and then declined gradually. 3. The silage intake level was low. 4. The swallowed silage did not accumulate at the cardiac region but was forced into the dorsal sac of the rumen by the contractions of the reticulum and cranial sac of the rumen. For regurgitation the solid particles had to return via the ventral and cranial sac of the rumen into the reticulum. 5. Liquid reticular contents with floating solid particles were aspirated into the oesophagus during the maximum of the regurgitation contraction of the reticulum. 6. The rumination activity during the day presented a high proportion of pseudo-rumination cycles whereas during the night the rumination became progressively normal. 7. Pseudo-rumination was caused by delayed return of the fibrous silage particles into the reticulum. Thus in pseudo-rumination the regurgitated material consisted predominantly of fluid containing only a small quantity of solid particles. 8. The results explain why long-chopped silage intake is associated with pseudo-rumination, a lower breakdown of particles and a waste of digestion time.
Animal Feed↗
Inhibition of reverse peristalsis of the intestine by domperidone.
In two dogs the effect of domperidone (0.5 mg/kg BW i.v.) on retroperistaltism produced by apomorphine (3-10 mg s.c.) was studied. Reverse peristalsis was characterized by strong and long lasting contractions of the duodenum. Domperidone inhibited, in 10 out of 11 experiments, reverse peristalsis and reflux of intestinal contents. It is well known that domperidone inhibits emesis in dogs and humans but it has not been studied whether preceding retroperistaltism is also inhibited. Therefore the effect of domperidone on retroperistaltism was investigated in two dogs.
Animals↗
Gastric and duodenal motility in relation to duodenogastric reflux in healthy dogs.
Motility of the antrum, pyloric sphincter, duodenal bulb and proximal duodenum was recorded in unanesthetized dogs. The timing between pyloric and duodenal contractions was imperfect in the interdigestive and also in the digestive state. The duodenal bulb often contracted before the pylorus was completely closed. Duodenogastric reflux occurred occasionally during gastric emptying, during the interdigestive activity and after stimulation of duodenal motility by hydrochloric acid. Reflux was produced by atypical contractions of the duodenal bulb.
Animals↗
Retroperistaltism and duodenogastric reflux in dogs.
Motility of the antrum, pyloric sphincter, duodenal bulb and proximal duodenum was recorded in unanesthetized dogs. Retroperistaltism and reflux of intestinal contents were regularly produced by apomorphine and occurred often with or without vomiting when large amounts of hydrochloric acid were infused or delivered into the small intestine. Retroperistaltism was found occasionally after intravenous infusion of adrenalin, carbachol or pentagastrin. Reverse peristalsis was characterized by strong and long lasting contractions of the duodenum migrating orad.
Animals↗
[Strain gauge transducer for recording gastrointestinal motility in unanesthetized animals (author's transl)].
An improved method for preparing strain gauge transducers for recording gastrointestinal motility is described. The advantages and disadvantages of the strain gauge transducers in comparison to other methods are discussed.
Animals↗