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

1990 ◽  
Vol 259 (1) ◽  
pp. G78-G85 ◽  
Author(s):  
M. L. Siegle ◽  
H. R. Schmid ◽  
H. J. Ehrlein
Keyword(s):  
Amino Acids ◽  
Small Intestine ◽  
Gastric Emptying ◽  
Motor Pattern ◽  
Inhibitory Effects ◽  
Contraction Force ◽  
Motor Patterns ◽  
Proximal Small Intestine ◽  
Dose Dependent ◽  
Different Doses

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, 0.6, and 0.9 kJ/min). The computerized analysis of motor patterns was focused on the differentiation between stationary and propagated contractions recorded by closely spaced extraluminal strain gauges. All three nutrients exerted inhibitory effects on gastric emptying and on contraction force and frequency of the proximal small intestine. Additionally, the propulsive motor pattern induced by the acaloric meal was modulated by reducing the number of contraction waves and their length of spread. All the effects were dose dependent. Among the three nutrients, glucose significantly changed motility at lower doses compared with amino acids and oleate. We conclude that in dogs the ileal brake mechanism is induced by all three nutrients and that it influences not only contraction force and frequency but also the motor patterns of the proximal small intestine.

Is nitric oxide the final mediator regulating the migrating myoelectric complex cycle?

1995 ◽  
Vol 268 (2) ◽  
pp. G207-G214 ◽  
Author(s):  
A. Rodriguez-Membrilla ◽  
V. Martinez ◽  
M. Jimenez ◽  
E. Gonalons ◽  
P. Vergara
Keyword(s):  
Nitric Oxide ◽  
Small Intestine ◽  
Motor Pattern ◽  
No Synthase ◽  
Phase Iii ◽  
Motor Patterns ◽  
No Donor ◽  
Postprandial State ◽  
Synthase Inhibitor

The main objective was to study the role of nitric oxide (NO) in the conversion of migrating myoelectric complexes (MMC) to the irregular electrical activity characteristic of the postprandial state. Both rats and chickens were implanted with electrodes for electromyography in the small intestine. Intravenous infusion of NG-nitro-L-arginine (L-NNA), a NO synthase inhibitor, induced an organized MMC-like pattern in fed rats. Infusion of sodium nitroprusside, a NO donor, disrupted the MMC, inducing a postprandial-like motor pattern in fasting rats. Similarly, in chickens L-NNA mimicked the fasting pattern, consisting of a shortening of phase II, enlargement of phase III, orad displacement of the origin of the MMC, and an increase in the speed of phase III propagation. An inhibition of NO synthesis seems to be involved in the induction of the fasting motor pattern, whereas an increase of NO mediates the occurrence of the fed pattern. It is suggested that NO might be the final mediator in the control of small intestine motor patterns.

Modulation of the crayfish swimmeret rhythm by octopamine and the neuropeptide proctolin

1987 ◽  
Vol 58 (3) ◽  
pp. 584-597 ◽  
Author(s):  
B. Mulloney ◽  
L. D. Acevedo ◽  
A. G. Bradbury
Keyword(s):  
Spontaneous Activity ◽  
Motor Neurons ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Motor Pattern ◽  
Threshold Concentration ◽  
Power Stroke ◽  
Motor Patterns ◽  
Dose Dependent ◽  
Characteristic Motor

1. The swimmeret system can be excited by perfusing the neuropeptide proctolin through the isolated ventral nerve cord of the crayfish. Previously silent preparations begin to generate a characteristic motor pattern, the swimmeret rhythm, in the nerves that innervate the swimmerets. The response to proctolin is dose dependent and reversible. The threshold concentration of proctolin perfused through the ventral artery is approximately 10(-8) M. The EC50 is 1.6 X 10(-6) M. 2. Proctolin-induced motor patterns have periods and phases similar to those of spontaneously generated motor patterns. The durations of the bursts of impulses in power-stroke motor neurons generated in the presence of proctolin are, however, significantly longer than those that occur during spontaneous activity. 3. DL-Octopamine inhibits the swimmeret system, both when the system is spontaneously active and when it has been excited by proctolin. The inhibition by octopamine is dose dependent and reversible. The threshold for inhibition is approximately 10(-6) M, and the EC50 is approximately 5 X 10(-5) M. 4. Octopamine's effect is mimicked by its agonists, synephrine and norepinephrine. Synephrine has a lower threshold concentration than does octopamine, but norepinephrine is much less effective than octopamine. 5. Octopamine's inhibition is partially blocked by an antagonist, phentolamine. 6. Phentolamine also blocks inhibition of the swimmeret system by inhibitory command interneurons. This block is dose dependent and can be partially overcome by stimulating the command interneurons at higher frequencies. 7. Perfusion with 11 other suspected crustacean neurotransmitters and transmitter analogues did not similarly excite or inhibit the swimmeret system, so we suggest that proctolin and octopamine are transmitters used by the neurons that normally control expression of the swimmeret rhythm.

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

1990 ◽  
Vol 68 (12) ◽  
pp. 1495-1502 ◽  
Author(s):  
M. L. Siegle ◽  
S. Bühner ◽  
H. J. Ehrlein
Keyword(s):  
Motor Pattern ◽  
Strain Gauges ◽  
Motor Patterns ◽  
Temporal And Spatial Distribution ◽  
Jejunal Segment ◽  
Duodenal Motility ◽  
Computerized Analysis ◽  
Proximal Small Intestine ◽  
Temporal And Spatial ◽  
Stimulation Of

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 were more pronounced after the nutrient than after the acaloric meal. After the nutrient meal, but not after the acaloric meal, 5-HTP additionally enhanced the number of both duodenal and jejunal contractions per minute and increased the force of duodenal contractions. The acaloric meal induced significant differences in the motor patterns between the duodenum and the adjacent jejunum. 5-HTP abolished these differences owing to a relatively stronger stimulation of duodenal motility. 5-HTP did not affect gastric emptying of both meals. We conclude (i) that 5-HTP is a potent stimulator of propagated contractions both in the duodenum and the adjacent jejunal segment and (ii) that intestinal motor patterns can be regulated independently of gastric emptying.Key words: 5-hydroxytryptophan, duodenum, jejunum, gastrointestinal motility, length of contraction spread, computerized analysis.

Rhythmic oscillating complexes in gastrointestinal tract of chickens: a role for motilin

1997 ◽  
Vol 272 (4) ◽  
pp. G916-G922 ◽  
Author(s):  
A. Rodriguez-Sinovas ◽  
M. Jimenez ◽  
P. De Clercq ◽  
T. L. Peeters ◽  
P. Vergara
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Gastrointestinal Motility ◽  
High Speed ◽  
Mammalian Species ◽  
Motor Pattern ◽  
Phase Iii ◽  
Motility Pattern ◽  
Plasma Motilin ◽  
Dose Dependent

Rhythmic oscillating complex (ROC) is a highly organized gastrointestinal motility pattern recently described in fasted avian species. ROCs show several high-speed aborad-propagated contractions that progressively change into others of orad direction. In addition, chickens show migrating motor complexes (MMC) in both fed and fasting states. Recently, motilin was isolated and characterized from chicken small intestine. Accordingly, the aim of this study was to learn whether chicken motilin might be involved in either ROC or MMC induction. Electromyographic recordings were obtained from different areas of the gastrointestinal tract of chickens while motilin was infused. The response to chicken motilin was dose dependent in both fed and fasted animals; a bolus of 4 x 10(-11) mol/kg (n = 5) did not modify the intestinal motor pattern, whereas 4 x 10(-10) and 4 x 10(-9) mol/kg (n = 5 each) induced a complete ROC pattern of 5.2 +/- 0.6 and 10.8 +/- 0.9 min, respectively. ROCs induced by chicken motilin presented exactly the same pattern as that described during a spontaneous ROC. Furthermore, motilin concentration in plasma, measured by radioimmunoassay, increased during a spontaneous ROC. This study suggests that chicken motilin triggers an ROC in chickens. The fact that plasma motilin levels increased during spontaneous ROC strongly suggests that motilin is involved in the induction of the ROC pattern. Motilin seems to play a different role in avian and mammalian species, because a phase III of the MMC was never induced by motilin infusion.

scholarly journals Epigastric Fullness

2000 ◽  
Vol 14 (suppl d) ◽  
pp. 141D-144D
Author(s):  
Georg Stacher
Keyword(s):  
Small Intestine ◽  
Targeted Therapy ◽  
Gastric Emptying ◽  
Motor Function ◽  
Delayed Gastric Emptying ◽  
Benign Disease ◽  
Clinical Impression ◽  
Proximal Small Intestine ◽  
Gastric Motor Function ◽  
Underlying Disorder

Epigastric fullness may be caused by a disordered gastric motor function, resulting in delayed gastric emptying, but may also be caused by rapid emptying, leading to a distention of the proximal small intestine. A rational diagnostic approach to a patient complaining of epigastric fullness is needed to reveal the underlying disorder or disease and to enable an adequate, targeted therapy. The clinical impression based on symptoms is unreliable and cannot distinguish function disorders and benign disease from severe conditions.

scholarly journals Effects of wheat-flour and oat mill fractions on jejunal flow, starch degradation and absorption of glucose over an isolated loop of jejunum in pigs

1994 ◽  
Vol 72 (2) ◽  
pp. 299-313 ◽  
Author(s):  
Helle N. Johansen ◽  
K. E. Bach Knudsen
Keyword(s):  
Small Intestine ◽  
Gastric Emptying ◽  
Wheat Flour ◽  
Starch Content ◽  
Mean Transit Time ◽  
Glucose Absorption ◽  
Major Influence ◽  
Starch Degradation ◽  
Proximal Small Intestine ◽  
Rate Of Absorption

The effect of cereal-based diets varying in dietary fibre (DF) on gastric emptying and glucose absorption over an isolated loop of jejunum was studied in four pigs fitted with two sets of re-entrant cannulas. The pigs were fed on either a wheat-flour diet or three diets based on oat flour (endosperm), rolled oats or oat bran containing different amounts of soluble DF. Mean transit time (MTT) of liquid estimated from the output from the first jejunal cannula was significantly higher with the two diets having the highest DF content, but MTT of dry matter (DM), starch, xylose and neutral non-starch polysaccharides (nNSP) was not correlated directly to the DF content of the diet. DF had a stimulatory effect on secretion of gastrointestinal juices, but the effect was not linearly correlated with the DF content of the diet. Starch was significantly degraded in digesta collected within 30 min after feeding with malto-oligosaccharides accounting for 140–147 g/kg total starch. The degradation was more extensive with higher DF and lower starch content of the diet. However, taking into account the differences in jejunal flow, the amount of malto-oligosaccharides available for absorption in the first 0.5 h decreased with higher levels of DF in the oat-based diets. The absorption of glucose from the isolated loop was 18–34 g/m intestine over an 8 h period with no significant differences between diets. This corresponded to a non-significant decrease in recovery of starch from 0.91 to 0.82 with increasing levels of DF and decreasing levels of starch in the diet. This suggests that the capacity for absorption of large doses of starch entering the proximal small intestine after ingestion of a carbohydrate-rich cereal-based diet has a major influence on the absorption at this site. Consequently any effect of DF on glucose absorption may be exerted either through the rate of gastric emptying or by impaired rate of absorption more distal in the small intestine and not by displacement of the site for starch absorption.

scholarly journals Dietary Supplementation with Casein Glycomacropeptide, Leucine and Tryptophan Reduces Plasma Amino Acid Levels in Men

2021 ◽  
pp. 1-28
Author(s):  
Erik Roj Larsen ◽  
Anette Juel ◽  
Erik Jensen ◽  
Tristan R. Hollyer ◽  
Gregers Wegener
Keyword(s):  
Amino Acids ◽  
Area Under The Curve ◽  
Aromatic Amino Acids ◽  
Bipolar Disorders ◽  
Double Blind ◽  
Amino Acid Levels ◽  
The One ◽  
Dose Response Study ◽  
Dose Dependent ◽  
Different Doses

Abstract Background The treatment of mania in bipolar disorders needs to be more efficient, as the manic condition creates severe problems for the patient when it comes to work, finances, relationships, and health. This proof-of-concept study examines to what extent casein glycomacropeptide (CGMP) may reduce the precursors of dopamine, phenylalanine, and tyrosine, in plasma, and therefore be a potential new intervention to treat acute manic episodes. Method The study was designed as a double-blind randomised dose-response study of CGMP (with added leucine and tryptophan) in 15 healthy men, receiving 3 different doses of CGMP with an interval of at least 14 days. Results Administration of CGMP produced a dose dependent depletion of plasma aromatic amino acids. The total area under the curve of plasma ratios of phenylalanine-tyrosine compared to the level of leucine-isoleucine-valine-tryptophan was CGMP(20g): 3.648 [SE:0.3281]; CGMP(40g): 2.368 [SE:0.1858]; CGMP(60g)1.887 [SE:0.2591]. A comparison of the groups showed a dose dependent statistical difference, with a One-Way ANOVA summary (Dunnett) F= 11.87, p= 0.0003, CGMP 20g vs CGMP 40g, p= 0.0042, CGMP 20g vs CGMP 60g, p= 0.0002. No significant side effects were observed. Conclusions This study demonstrate CGMP is a well-tolerated and effective mixture, and that 60 g CGMP produced the highest depletion of plasma aromatic amino acids (phenylalanine and tyrosine). The effect seems to be highest after 3-4 hours. We therefore conclude that this dose should be the one considered for future studies involving CGMP in humans.

Chloride-dependent intestinal transport of imino and beta-amino acids in the guinea pig and rat

1994 ◽  
Vol 266 (3) ◽  
pp. R997-R1007 ◽  
Author(s):  
L. K. Munck ◽  
B. G. Munck
Keyword(s):  
Amino Acids ◽  
Small Intestine ◽  
Guinea Pig ◽  
Intestinal Transport ◽  
Isobutyric Acid ◽  
Acid Activation ◽  
Beta Alanine ◽  
Imino Acid ◽  
Proximal Small Intestine

The present study extends the observations of chloride-dependent intestinal amino acid carriers to the guinea pig and the rat using the technique of in vitro influx across the brush-border membrane of intact epithelium. Transport rates of D-glucose and L-amino acids are lowest in guinea pig proximal small intestine and are constant from midjejunum through distal ileum, except for leucine. The guinea pig possesses a sodium- and chloride-dependent, high-affinity, very low-capacity carrier of beta-amino acids for which taurine and beta-alanine compete and for which the Na(+)-taurine activation stoichiometry is 2.1 +/- 0.3:1. The imino acid carrier of the guinea pig is also chloride dependent with a Na(+)-Cl(-)-2-methylamino-isobutyric acid activation stoichiometry of 1.8 +/- 0.1:0.7 +/- 0.3:1. In contrast, the rat imino acid carrier is chloride independent and transport rates vary insignificantly along the small intestine. The rat taurine carrier has its maximal transport rate in midjejunum. It is chloride dependent but does not transport beta-alanine.

Neural isolation of the entire canine stomach in vivo: effects on motility

1989 ◽  
Vol 257 (1) ◽  
pp. G30-G40 ◽  
Author(s):  
J. A. Van Lier Ribbink ◽  
M. G. Sarr ◽  
M. Tanaka
Keyword(s):  
Small Intestine ◽  
Motor Activity ◽  
Motor Pattern ◽  
Phase Iii ◽  
Myoelectric Activity ◽  
Motor Patterns ◽  
Gastric Motor Activity ◽  
Plasma Motilin ◽  
In Vivo Effects

This study was designed to determine the effects of transection of all extrinsic and enteric neural continuity to the entire stomach on motility patterns of the stomach and small intestine. Five dogs were subjected to a model of orthotopic autotransplantation of the stomach to achieve an in vivo, "neurally isolated" stomach. Manometric catheters and serosal electrodes were implanted. A cyclic motor pattern occurred during fasting and was closely coordinated temporally with the migrating motor complex (MMC) in the small bowel. The period of the cyclic gastric motor activity did not differ from the period of the MMC in the small intestine [121 +/- 8 vs 124 +/- 10 (means +/- SE) min, P = 0.4], but the periods of both were greater than in control dogs (93 +/- 5 min, P less than 0.05). Tachygastria accounted for 36 +/- 13% of fasting myoelectric activity in the neurally isolated dogs and for less than 1% in control dogs. Plasma concentration of motilin was greatest during the phase III-like gastric motor activity; exogenous motilin induced premature phase III-like activity in the stomach and small intestine. Feeding abolished the cyclic motor activity in the stomach and decreased plasma motilin concentration. These data suggest that hormonal factors, and not extrinsic or intrinsic neural continuity to the stomach, may control both the initiation of a cyclic interdigestive gastric motor pattern and its temporal coordination with motor patterns in the small intestine.

Inhibition of gastric emptying by sodium oleate depends on length of intestine exposed to nutrient

1990 ◽  
Vol 259 (6) ◽  
pp. G1031-G1036 ◽  
Author(s):  
H. C. Lin ◽  
J. E. Doty ◽  
T. J. Reedy ◽  
J. H. Meyer
Keyword(s):  
Small Intestine ◽  
Gastric Emptying ◽  
Feedback Control ◽  
Sodium Oleate ◽  
Negative Feedback ◽  
Inhibitory Effect ◽  
Fat Absorption ◽  
Molar Basis ◽  
Intestinal Fistulas ◽  
Dose Dependent

Previously, we reported that inhibition of gastric emptying by glucose or acids depends on the length of gut exposed to the inhibitor [Gastroenterology 95: A877, 1988; Am. J. Physiol. 256 (Gastrointest. Liver Physiol. 19): G404-G411, 1989]. In this study, we hypothesized that feedback control by fat may be similarly regulated. In dogs with chronic intestinal fistulas, we compared the intensity of intestinal feedback when different lengths of the small intestine were exposed to meals of 3, 9, or 27 mM sodium oleate. We found that 1) inhibition of liquid emptying was dose dependent, 2) intensity of negative feedback was dependent on both the concentration of the oleate and the length of gut exposed to fat, 3) full inhibitory effect was achieved with exposure of fat to 150 cm of gut, 4) inhibition from the distal one-half of gut was less potent than that generated from the proximal one-half of gut, and 5) on a molar basis oleate was 20 times as effective as glucose at inhibition of gastric emptying and that this difference was related to the slower rate of fat absorption.

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