Inhibition of intestinal degradation of somatostatin by rat milk

1990 ◽  
Vol 258 (3) ◽  
pp. G426-G431
Author(s):  
R. K. Rao ◽  
O. Koldovsky ◽  
T. P. Davis
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Soluble Fraction ◽  
In Vitro Degradation ◽  
Weanling Rats ◽  
Gastric Lumen ◽  
Milk Casein ◽  
Soluble Fractions ◽  
Somatostatin 14

In vitro degradation of 125I-labeled somatostatin-14 (Tyr11) [I-SS-14(Tyr11)] by luminal flushings of rat gastrointestinal segments was studied to characterize the fate of somatostatin in the gastrointestinal lumen. In addition, we evaluated the effect of rat milk as a potential inhibitor of luminal degradation of 125I-SS-14(Tyr11). Degradation of 125I-SS-14(Tyr11) was not detected in stomach flushings from either suckling or weanling rats. Luminal flushings from the small intestine degraded 125I-SS-14(Tyr11), with a gradient increase of activity from duodenum to midjejunum (degradation in suckling rat midjejunum and ileum was about five times lower than that in weanling rat). Degradation of 125I-SS-14(Tyr11) by luminal flushings of suckling rat midjejunum was dose dependently inhibited by rat milk casein and soluble fractions. Inhibitory activity of rat milk soluble fraction was heat labile and several times more potent than that of casein fraction. Casein fraction appeared to be stable at 100 degrees C for up to 30 min of exposure. These studies suggest that somatostatin is stable in the gastric lumen and that milk protects somatostatin from intestinal luminal proteolysis, indicating a possible physiological significance of milk-borne SS-14 for the suckling rat gastrointestinal tract.

In vitro degradation of angiotensin II (A-II) by human placental subcellular fractions, pregnancy sera and purified placental aminopeptidases

1985 ◽  
Vol 110 (1) ◽  
pp. 135-139 ◽  
Author(s):  
Shigehiko Mizutani ◽  
Haruyuki Akiyama ◽  
Osamu Kurauchi ◽  
Hiroyuki Taira ◽  
Osamu Narita ◽  
...  
Keyword(s):  
Amino Acids ◽  
Angiotensin Ii ◽  
High Performance ◽  
Leucine Aminopeptidase ◽  
Soluble Fraction ◽  
In Vitro Degradation ◽  
Aminopeptidase A ◽  
Aminopeptidase P ◽  
Soluble Fractions

Abstract. The degradation of angiotensin II (Asp1-Arg2-Val3-Tyr4-Ile5-His6-Pro7-Phe8: A-II) by human placental particulate and soluble fractions, pregnant and non-pregnant sera, and highly purified placental enzymes such as placental leucine aminopeptidase P-LAP (microsomal), retroplacental serum P-LAP (soluble), aminopeptidase A and post-proline endopeptidase, was studied by measuring liberated amino acids by high performance liquid chromatography. Placental particulate and soluble fractions degraded A-II almost completely into single amino acids. The purified P-LAP (microsomal) actively liberated five amino acids from the N-terminal. The placental particulate fraction containing P-LAP (microsomal) also actively liberated these amino acids. The purified aminopeptidase A liberated Asp1 very actively as expected. When the ratio of the velocity of liberation of each amino acid to P-LAP activity measured with leu-p-nitroanilide as a substrate was calculated, placental soluble fraction liberated Asp1 very actively, but the liberation rate of Asp1 with the purified P-LAP (soluble) was very low. Therefore it seems that the enzyme in the placental soluble fraction and pregnancy serum responsible for the Asp1 liberation is not P-LAP (soluble), but aminopeptidase A. The mixture of purified P-LAP (soluble) and aminopeptidase A showed higher liberation rate of Arg2 and Val3 than that with purified aminopeptidase A alone, demonstrating that once the N-terminal Asp1 was liberated, the P-LAP (soluble) attacks the shorter peptide (angiotension III) very actively. It was concluded that P-LAP (microsomal) together with aminopeptidase A seem to contribute greatly to the degradation of A-II in pregnant women.

Luminal digestion of lactoferrin in suckling and weanling rats

1987 ◽  
Vol 253 (3) ◽  
pp. G397-G403 ◽  
Author(s):  
J. R. Britton ◽  
O. Koldovsky
Keyword(s):  
Small Intestine ◽  
Polyacrylamide Gel Electrophoresis ◽  
Young Animal ◽  
Product Analysis ◽  
Weanling Rats ◽  
Total Product ◽  
Two Peaks ◽  
Hydrolysis Of ◽  
Soluble Material

The development of luminal digestion of lactoferrin was evaluated in vitro by incubating 125I-labeled lactoferrin with fluid flushed from the stomach and small intestine of 12-day-old suckling and 31-day-old weanling rats, followed by measurement of radioactivity in trichloroacetic acid-soluble material. Gastric hydrolysis of lactoferrin at pH 3.2 in the weanling was 20-fold greater than that in the suckling. In the small intestine at neutral pH, luminal degradation of lactoferrin was minimal in the suckling but increased significantly after weaning, with maximal degradative capacity demonstrable in the midjejunum. Sephadex G-75 chromatography of intestinal acid-soluble breakdown products revealed two peaks of radioactivity, each comprising 40-45% of the total product; analysis of intestinal acid-precipitable products by polyacrylamide gel electrophoresis yielded several discrete lower molecular weight species. Food deprivation for 12 h/100 g body wt decreased lactoferrin degradation in the weanling jejunum and midjejunum. Our findings suggest that lactoferrin digestion may vary with respect to postnatal age of the organism, segment of the gastrointestinal tract, and dietary state. In the young animal, lactoferrin degradation is minimal, and consequently its potential for biological function may be high.

In vitro Gastrointestinal Models for Prebiotic Carbohydrates: A Critical Review

2019 ◽  
Vol 25 (32) ◽  
pp. 3478-3483 ◽  
Author(s):  
Oswaldo Hernandez-Hernandez
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Brush Border ◽  
Critical Review ◽  
In Vitro Digestibility ◽  
Human Gastrointestinal Tract ◽  
Intestinal Brush Border ◽  
Small Intestinal ◽  
Existing Data

Background: In the last decade, various consortia and companies have created standardized digestion protocols and gastrointestinal simulators, such as the protocol proposed by the INFOGEST Consortium, the simulator SHIME, the simulator simgi®, the TIM, etc. Most of them claim to simulate the entire human gastrointestinal tract. However, few results have been reported on the use of these systems with potential prebiotic carbohydrates. Methods: This critical review addresses the existing data on the analysis of prebiotic carbohydrates by different in vitro gastrointestinal simulators, the lack of parameters that could affect the results, and recommendations for their enhancement. Results: According to the reviewed data, there is a lack of a realistic approximation of the small intestinal conditions, mainly because of the absence of hydrolytic conditions, such as the presence of small intestinal brush border carbohydrases that can affect the digestibility of different carbohydrates, including prebiotics. Conclusion: There is a necessity to standardize and enhance the small intestine simulators to study the in vitro digestibility of carbohydrates.

scholarly journals Enzyme activity after resealing within ghost erythrocyte cells, and protection by α-crystallin against fructose-induced inactivation

2002 ◽  
Vol 368 (3) ◽  
pp. 865-874 ◽  
Author(s):  
Barry K. DERHAM ◽  
John J. HARDING
Keyword(s):  
Enzyme Activity ◽  
Molecular Chaperone ◽  
Soluble Fraction ◽  
Erythrocyte Ghosts ◽  
Ghost Cell ◽  
Chaperone Function ◽  
Zero Time ◽  
Soluble Fractions

The role of α-crystallin as a molecular chaperone has been shown in many in vitro studies. In the present paper, we report on the chaperone function of α-crystallin within resealed erythrocyte ghosts. Eight enzymes were individually resealed within erythrocyte ghosts and assayed at zero time and at 24h. The ghost cell suspension was separated into soluble and membrane fractions. Five of the enzymes had significantly greater enzyme activity after 24h than the control within the soluble fractions. Fructation caused a decrease in enzyme activity (relative to the control). Resealing of α-crystallin within the ghost cell alongside the enzymes protected against inactivation by fructose within the soluble fraction.

Ileal and hindgut fermentation in the growing pig fed a human-type diet

2020 ◽  
Vol 124 (6) ◽  
pp. 567-576 ◽  
Author(s):  
Anna M. E. Hoogeveen ◽  
Paul J. Moughan ◽  
Edward S. de Haas ◽  
Paul Blatchford ◽  
Warren C. McNabb ◽  
...  
Keyword(s):  
Body Weight ◽  
Organic Matter ◽  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Taxonomic Composition ◽  
Human Type ◽  
Growing Pig ◽  
Microbial Inocula

AbstractDietary fibre fermentation in humans and monogastric animals is considered to occur in the hindgut, but it may also occur in the lower small intestine. This study aimed to compare ileal and hindgut fermentation in the growing pig fed a human-type diet using a combined in vivo/in vitro methodology. Five pigs (23 (sd 1·6) kg body weight) were fed a human-type diet. On day 15, pigs were euthanised. Digesta from terminal jejunum and terminal ileum were collected as substrates for fermentation. Ileal and caecal digesta were collected for preparing microbial inocula. Terminal jejunal digesta were fermented in vitro with a pooled ileal digesta inoculum for 2 h, whereas terminal ileal digesta were fermented in vitro with a pooled caecal digesta inoculum for 24 h. The ileal organic matter fermentability (28 %) was not different from hindgut fermentation (35 %). However, the organic matter fermented was 66 % greater for ileal fermentation than hindgut fermentation (P = 0·04). Total numbers of bacteria in ileal and caecal digesta did not differ (P = 0·09). Differences (P < 0·05) were observed in the taxonomic composition. For instance, ileal digesta contained 32-fold greater number of the genus Enterococcus, whereas caecal digesta had a 227-fold greater number of the genus Ruminococcus. Acetate synthesis and iso-valerate synthesis were greater (P < 0·05) for ileal fermentation than hindgut fermentation, but propionate, butyrate and valerate synthesis was lower. SCFA were absorbed in the gastrointestinal tract location where they were synthesised. In conclusion, a quantitatively important degree of fermentation occurs in the ileum of the growing pig fed a human-type diet.

COMPARISON OF THE METABOLISM OF TESTOSTERONE UNDECANOATE AND TESTOSTERONE IN THE GASTROINTESTINAL WALL OF THE RAT IN VITRO AND IN VIVO

1977 ◽  
Vol 86 (1) ◽  
pp. 216-224 ◽  
Author(s):  
J. Geelen ◽  
A. Coert ◽  
R. Meijer ◽  
J. van der Vies
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Portal Vein ◽  
Oral Administration ◽  
Small Extent ◽  
Great Similarity ◽  
Testosterone Undecanoate ◽  
Different Parts

ABSTRACT The metabolism of testosterone undecanoate (TU) and testosterone (T) is studied in the gastrointestinal wall of the rat in vitro. A comparison is made with the in vivo metabolism of these compounds in the rat. The major metabolite first appearing during incubation of TU with the small intestine is T. Incubation of TU or T with the small intestine reveals a great similarity between the metabolite patterns obtained. This is also the case with the patterns derived from portal vein plasma upon oral administration of TU and T. Incubation of different parts of the gastrointestinal tract with TU or T shows that the greatest metabolic activity is located in the wall of the small intestine. Unlike T, TU is metabolized only to a small extent in the wall of the stomach and the large intestine.

Microorganisms in the gastrointestinal tract of the rat prevent absorption of the mutagen–carcinogen 3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole

1993 ◽  
Vol 39 (9) ◽  
pp. 841-845 ◽  
Author(s):  
Xue Bin Zhang ◽  
Yoshiyuki Ohta
Keyword(s):  
Small Intestine ◽  
Lactic Acid ◽  
Gastrointestinal Tract ◽  
Lactic Acid Bacteria ◽  
Intestinal Bacteria ◽  
Gastrointestinal Absorption ◽  
Aqueous Methanol ◽  
Freeze Dried

The extent to which lactic acid bacteria, intestinal bacteria, and yeast from the gastrointestinal tract of rats suppress the absorption of 3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole (Trp-P-1) was investigated. Trp-P-1 was absorbed from the small intestine very rapidly, but in the stomach it was slowly absorbed, requiring 1 or 2 h after administration. When mixtures of Trp-P-1 and freeze-dried microorganisms were administered to rats for 1 h, the amounts of Trp-P-1 absorbed from the small intestine were significantly reduced, and the levels of Trp-P-1 in blood decreased by 40.4–64.7% compared with a control in which only Trp-P-1 was administered. There were no significant differences between the organisms used. In vitro, freeze-dried cells of the strains tested bound 51-97% of Trp-P-1. The Trp-P-1 bound to cells was effectively extracted by aqueous methanol, ethanol, ammonia (50 g/L), and solutions of MgCl2 and CaCl2 (100 mM/mL), but little was extracted by water and solutions of KCl, NaCl, and buffers at various pH values.Key words: Trp-P-1, gastrointestinal absorption, binding, intestinal bacteria, mutagen–carcinogen.

scholarly journals A review of the physiology of the canine digestive tract related to the development ofin vitrosystems

1998 ◽  
Vol 11 (1) ◽  
pp. 45-69 ◽  
Author(s):  
Marianne Smeets-Peeters ◽  
Tim Watson ◽  
Mans Minekus ◽  
Robert Havenaar
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Digestive Tract ◽  
Healthy Adult ◽  
Human Beings ◽  
Ph Values ◽  
Transit Times ◽  
Food And Nutrition ◽  
Different Types

AbstractFood and nutrition studies in animals and human beings often meet with technical difficulties and sometimes with ethical questions. An alternative to research in living animals is the dynamic multicompartmentalin vitromodel for the gastrointestinal tract described by Minekuset al.(1995) and Havenaar & Minekus (1996). The dynamic conditions that are simulated in this model are peristaltic movements, transit times, pH responses, secretion of enzymes and electrolytes and absorption of nutrients and water. To obtain data for anin vitromodel of the dog gastrointestinal tract, the literature was surveyed for physiological responses to different types of dog food. These included: values of enzyme activities, electrolyte concentrations, gastric emptying and intestinal transit times, pH values, secretion and composition of bile and absorption rates in different parts of the dog gastrointestinal tract. The review focuses on research carried out on healthy, adult dogs of 10–20 kg and on parameters related to the oral cavity, stomach and small intestine. This literature research gives sufficient data on the physiology of the canine digestive tract for the development of anin vitrodynamic model that adequately simulates the functions of the stomach and small intestine of the dog.

Survival of a probiotic-containing product using capsule-within-capsule technology in an in vitro model of the stomach and small intestine (TIM-1)

2020 ◽  
Vol 11 (4) ◽  
pp. 403-409
Author(s):  
K. Venema ◽  
J. Verhoeven ◽  
C. Beckman ◽  
D. Keller
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
In Vitro Model ◽  
Additional Benefit ◽  
Outer Capsule ◽  
Probiotic Strains ◽  
Human Adults ◽  
Similar Survival ◽  
Vitro Model

The aim of the research was to compare the survival of a blend of five probiotic strains (2 bifidobacteria and 3 lactobacilli) in a capsule within capsule (Duocap®) containing Ahiflower® oil, as compared to the strains in the powder (with or without Ahiflower oil), or the strains when present in the inner capsule only. This was tested in a validated, dynamic in vitro model of the stomach and small intestine (TIM-1), simulating human adults. Experiments were performed both in the gastric compartment of the model, as well as in the complete system (stomach + small intestine). Survival of the strains after transit through the gastric compartment in the Duocap capsule was higher by about a factor of 1.5 compared to the other 3 variables. In these gastric experiments, the Ahiflower oil did not seem to have an additional benefit, in the sense that it did not increase survival over the strains alone. After transit through the complete gastrointestinal tract survival was approximately 2-fold higher for the strains within the Duocap capsule, compared to the strains within the inner capsule or the powder. In these experiments, Ahiflower oil did have an additional benefit. The survival of the strains in the combination of powder with Ahiflower oil showed a similar survival as that of the Duocap, although in the first few hours of the experiments survival of both species lagged behind, and only caught up at the end of the test. In conclusion, the developed capsule-in-capsule technology increased the amount of viable cells in the upper gastrointestinal tract, mainly due to the presence of the polyunsaturated fatty acids contained in the outer capsule, which particularly protected the blend of probiotics in the small intestine.

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