Factors controlling B12 uptake by intestinal sacs in vitro

Sacs of everted small intestine were incubated in bicarbonate-saline containing radioactive vitamin B12 with or without a source of gastric intrinsic factor (IF). In both the hamster and guinea pig the lowest ileum was most active in B12 uptake in the presence of intrinsic factor, the upper jejunum showing little or no uptake. Low temperature and anaerobic conditions completely abolished the stimulatory effect of IF on B12 uptake. Intrinsic factor did not bind to the intestinal wall in the absence of B12 (even in the presence of calcium ion) as the IF activity could be completely removed by gentle washing of the tissue. The vitamin and intrinsic factor must be present together to cause intestinal uptake of B12.

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Some species differences in the intrinsic factor stimulation of B12 uptake by small intestine in vitro

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1959.197.4.926 ◽

1959 ◽

Vol 197 (4) ◽

pp. 926-928 ◽

Cited By ~ 21

Author(s):

T. Hastings Wilson ◽

Elliott W. Strauss

Keyword(s):

Small Intestine ◽

Guinea Pig ◽

Species Differences ◽

Intrinsic Factor ◽

Vitamin B ◽

Guinea Pig Ileum ◽

Rat Intestine ◽

Intrinsic Factors ◽

Stimulation Of

Sacs of everted small intestine from a variety of animals were incubated in bicarbonate-saline containing vitamin B12 with and without intrinsic factor (IF). B12 uptake by rat intestine was stimulated only by its own intrinsic factor. Guinea pig ileum responded to all intrinsic factors tested (guinea pig, rat, hog, hamster, human being and rabbit). The intestines of hamster and rabbit were intermediate in specificity, responding to some, but not all, of the IF preparations. Species differences occur in both the intestine and intrinsic factor preparations. The guinea pig ileum was suggested as a possible assay for both hog and human IF.

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Effects of metabolic disturbances on potential difference across intestinal wall of rat

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1963.204.1.105 ◽

1963 ◽

Vol 204 (1) ◽

pp. 105-108 ◽

Cited By ~ 17

Author(s):

Masashi Sawada ◽

Tomoaki Asano

Keyword(s):

Small Intestine ◽

Low Temperature ◽

Intestinal Wall ◽

Potential Difference ◽

Rapid Decline ◽

Serosal Side ◽

Metabolic Disturbances ◽

Temperature Dependent ◽

Mucosal Side

The potential difference across the wall of the small intestine was determined in vitro under a variety of conditions using rats. When the normal Ringer's containing 200 mg/100 ml glucose was applied on both sides of the wall, the potential difference attained 5–9 mv, the serosal side being positive. The potential difference was temperature dependent, becoming reduced at low temperature, the temperature coefficient being 1.7 between 40 and 34 C. The potential difference was inhibited with 0.1 mm monoiodoacetic acid, 1 mm sodium azide, 0.1 mm dinitrophenol, and 50 µm ouabain applied on the mucosal side. Withdrawal and restitution of 200 mg/100 ml glucose on the mucosal side induced a rapid decline and recovery of the potential difference. The lowered potential difference was partially recovered by 200 mg/100 ml galactose but not by sorbitol.

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Specificity of sugar transport by the intestine of the hamster

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1960.198.1.99 ◽

1960 ◽

Vol 198 (1) ◽

pp. 99-102 ◽

Cited By ~ 68

Author(s):

T. Hastings Wilson ◽

Bernard R. Landau

Keyword(s):

Small Intestine ◽

Transport System ◽

Concentration Gradient ◽

Sugar Transport ◽

Intestinal Wall ◽

Sugar Derivatives

The specificity of the sugar transport system of the hamster small intestine was tested with 20 sugars and sugar derivatives not previously tested in this system. The absorption of sugars across the intestinal wall against a concentration gradient was tested with the everted sac technique in vitro. 3-Deoxyglucose, 4-0-methylgalactose, 6-deoxy-6-fluoroglucose and α-methylglucoside were transported while a variety of other sugars were not. From the data derived from the study of a total of 49 sugars tested in this system, certain generalizations are made as to the structural limitations of the sugar-absorbing capacity of the hamster intestine.

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Peristalsis in the Guinea Pig Small Intestine In Vitro Is Impaired by Acetaminophen but Not Aspirin and Dipyrone

Anesthesia & Analgesia ◽

10.1213/01.ane.0000139352.54676.18 ◽

2005 ◽

Vol 100 (1) ◽

pp. 120-127 ◽

Cited By ~ 10

Author(s):

Michael K. Herbert ◽

Rebecca Weis ◽

Peter Holzer ◽

Norbert Roewer

Keyword(s):

Small Intestine ◽

Guinea Pig

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Intestinal distribution of intrinsic factor and vitamin B12 absorption

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1965.208.1.14 ◽

1965 ◽

Vol 208 (1) ◽

pp. 14-17 ◽

Cited By ~ 5

Author(s):

Kunio Okuda ◽

Katsumi Sasayama

Keyword(s):

Small Intestine ◽

Vitamin B12 ◽

Large Intestine ◽

Intrinsic Factor ◽

Vitamin B ◽

Vitamin B12 Absorption ◽

Small Intestine Absorption

Evidence is presented that intrinsic-factor (IF) activity is present in the small intestine as far down as the ileal end. Physiologic doses of radioactive vitamin B12 without IF were applied directly into various levels of the intestine by surgical and other means in man and rats, and significant absorption was obtained from the small intestine. Absorption inhibition by ethylenediaminetetraacetate and its counteraction by Ca ion demonstrated that such absorption was dependent on IF action. The large intestine was shown to be incapable of physiologic absorption of vitamin B12, and IF was totally ineffective. It is proposed that physiologically, gastric IF descends with some activity in the small intestine, where more of the food vitamin B12 is liberated by digestion and subjected to IF.

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Mechanisms underlying nutrient-induced segmentation in isolated guinea pig small intestine

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00441.2006 ◽

2007 ◽

Vol 292 (4) ◽

pp. G1162-G1172 ◽

Cited By ~ 34

Author(s):

R. M. Gwynne ◽

J. C. Bornstein

Keyword(s):

Small Intestine ◽

Guinea Pig ◽

Motor Neurons ◽

Slow Wave ◽

Neural Circuit ◽

Circular Muscle ◽

Decanoic Acid ◽

Slow Waves ◽

Longitudinal Position

Mechanisms underlying nutrient-induced segmentation within the gut are not well understood. We have shown that decanoic acid and some amino acids induce neurally dependent segmentation in guinea pig small intestine in vitro. This study examined the neural mechanisms underlying segmentation in the circular muscle and whether the timing of segmentation contractions also depends on slow waves. Decanoic acid (1 mM) was infused into the lumen of guinea pig duodenum and jejunum. Video imaging was used to monitor intestinal diameter as a function of both longitudinal position and time. Circular muscle electrical activity was recorded by using suction electrodes. Recordings from sites of segmenting contractions showed they are always associated with excitatory junction potentials leading to action potentials. Recordings from sites oral and anal to segmenting contractions revealed inhibitory junction potentials that were time locked to those contractions. Slow waves were never observed underlying segmenting contractions. In paralyzed preparations, intracellular recording revealed that slow-wave frequency was highly consistent at 19.5 (SD 1.4) cycles per minute (c/min) in duodenum and 16.6 (SD 1.1) c/min in jejunum. By contrast, the frequencies of segmenting contractions varied widely (duodenum: 3.6–28.8 c/min, median 10.8 c/min; jejunum: 3.0–27.0 c/min, median 7.8 c/min) and sometimes exceeded slow-wave frequencies for that region. Thus nutrient-induced segmentation contractions in guinea pig small intestine do not depend on slow-wave activity. Rather they result from a neural circuit producing rhythmic localized activity in excitatory motor neurons, while simultaneously activating surrounding inhibitory motor neurons.

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Metabolism of ε-(γ-L-glutamyl)-L-lysine in the rat

British Journal Of Nutrition ◽

10.1017/s0007114575000335 ◽

1975 ◽

Vol 34 (2) ◽

pp. 291-296 ◽

Cited By ~ 13

Author(s):

G. Raczyński ◽

M. Snochowski ◽

S. Buraczewski

Keyword(s):

Small Intestine ◽

Intestinal Wall ◽

Rat Small Intestine ◽

Blood Proteins ◽

Vitro Experiment ◽

Comparative Tests ◽

In Vitro Experiment ◽

Body Tissues ◽

Everted Sacs

1. A study was made of the metabolism of ɛ-(γ-L-glutamyl)-L[4, 5-3H]lysine (GL) in the rat.2. The compound was largely absorbed from the intestine and metabolized. Labelled lysine was incorporated into blood proteins.3. In an in vitro experiment with everted sacs of rat small intestine, GL passed through the intestinal wall unchanged.4. The results of comparative tests using homogenates of different body tissues indicated that the kidneys were particularly active in hydrolysing GL. Their activity was nine times greater than that of the liver and eighteen times greater than that of the small intestine.

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Interaction of enkephalin and caerulein on guinea pig small intestine

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1983.244.1.g65 ◽

1983 ◽

Vol 244 (1) ◽

pp. G65-G70

Author(s):

W. M. Yau ◽

P. F. Lingle ◽

M. L. Youther

Keyword(s):

Small Intestine ◽

Guinea Pig ◽

Muscarinic Receptors ◽

Dose Response ◽

Response Curve ◽

Acetylcholine Release ◽

Control Level ◽

Release Studies ◽

Release Of Acetylcholine

This is a report on the effect of caerulein and methionine-enkephalin interaction on mechanical contraction and acetylcholine release in vitro. The ability of enkephalin to relax caerulein-induced contractions and the manner in which the caerulein dose-response curve was shifted in the presence of enkephalin strongly suggest that enkephalin and caerulein are functional antagonists in this system. The failure of enkephalin to alter the action of exogenous acetylcholine implies that such an antagonism is not mediated through a competition with postsynaptic muscarinic receptors on the muscle. Data from acetylcholine-release studies indicate that caerulein stimulation was dose related. As with the mechanical contractions, the release of acetylcholine in response to caerulein was inhibited by enkephalin. However, naloxone was capable of blocking this inhibition and restoring the release to its control level without interfering with caerulein stimulation. These data provide evidence for the modulatory roles of neuronal peptides in the cholinergic control of gut motility.

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