Heligmosomoides, polygyrus, (syn. Nematospiroides, dubius), (Nematoda): distribution and net fluxes of glucose, H2O, Na+, K+, and Cl− in the mouse small intestine

1984 ◽  
Vol 62 (1) ◽  
pp. 37-40 ◽  
Author(s):  
M. V. K. Sukhdeo ◽  
D. F. Mettrick
Keyword(s):  
Small Intestine ◽  
Water Flux ◽  
Heligmosomoides Polygyrus ◽  
Glucose Flux ◽  
Proximal Small Intestine ◽  
Normal Transmission ◽  
And Migration ◽  
Duodenal Lumen ◽  
Net Fluxes

Mice were infected with 150 larvae of Heligmosomoides, polygyrus, and the effect of the worms on net fluxes of glucose, H2O, and electrolytes was followed from days 1–21 postinfection (PI) by means of an in vivo, perfusion technique. Maximum recovery of larvae was 77% at 5 days PI, and 64% for adults at 12 days PI following their emergence and migration into the duodenal lumen between days 7 and 9 PI. Inflammation decreased rapidly from day 9 PI onwards. Net glucose flux significantly decreased during the emergence of the adult worms (7–9 days PI). Water flux decreased and Na+ fluxes became negative at 5 days PI; Na+ and Cl− fluxes were negative at 7 days PI. Following the relocation of the adult worms in the proximal small intestine, fluxes returned to their normal levels. The differential changes in the net fluxes of glucose, H2O, and electrolytes suggest the secretion of a toxinlike substance by the parasites. In the normal mouse host, small infections have a temporary pathophysiological effect on the intestinal mucosa, differing significantly from previous studies using the abnormal rat host and large larval infections. As normal transmission of H. polygyrus, is by contamination, small infections, as employed in this study, probably reflect the natural condition.

Small intestinal levels of the branched short-chain fatty acid isovalerate are elevated during infection with Heligmosomoides polygyrus and can promote helminth fecundity

2021 ◽  
Author(s):  
Mia H. E. Kennedy ◽  
Tara P. Brosschot ◽  
Katherine M. Lawrence ◽  
Rachael D. FitzPatrick ◽  
Jenna M. Lane ◽  
...  
Keyword(s):  
Small Intestine ◽  
Short Chain Fatty Acid ◽  
Helminth Infection ◽  
Chain Fatty Acid ◽  
Isovaleric Acid ◽  
Heligmosomoides Polygyrus ◽  
Bacterial Microbiota ◽  
Proximal Small Intestine ◽  
Small Intestinal ◽  
Helminth Fecundity

Heligmosomoides polygyrus is a helminth which naturally infects mice and is widely used as a laboratory model of chronic small intestinal helminth infection. While it is known that infection with H. polygyrus alters the composition of the host’s bacterial microbiota, the functional implications of this alteration are unclear. We investigated the impact of H. polygyrus infection on short-chain fatty acid (SCFA) levels in the mouse intestine and sera. We found that helminth infection resulted in significantly upregulated levels of the branched SCFA isovaleric acid, exclusively in the proximal small intestine, which is the site of H. polygyrus colonization. We next set out to test the hypothesis that elevating local levels of isovaleric acid was a strategy used by H. polygyrus to promote its own fitness within the mammalian host. To test this, we supplemented the drinking water of mice with isovalerate during H. polygyrus infection and examined whether this affected helminth fecundity or chronicity. We did not find that isovaleric acid supplementation affected helminth chronicity, however, we found that it did promote helminth fecundity, as measured by helminth egg output in the feces of mice. Through antibiotic-treatment of helminth-infected mice, we found that the bacterial microbiota was required in order to support elevated levels of isovaleric acid in the proximal small intestine during helminth infection. Overall, our data reveal that during H. polygyrus infection there is a microbiota-dependent localized increase in the production of isovaleric acid in the proximal small intestine and this supports helminth fecundity in the murine host.

scholarly journals Starch digestion kinetics and mechanisms of hydrolysing enzymes in growing pigs fed processed and native cereal-based diets

2019 ◽  
Vol 121 (10) ◽  
pp. 1124-1136 ◽  
Author(s):  
Bianca M. J. Martens ◽  
Thomas Flécher ◽  
Sonja de Vries ◽  
Henk A. Schols ◽  
Erik M. A. M. Bruininx ◽  
...  
Keyword(s):  
Small Intestine ◽  
Growing Pigs ◽  
Intestinal Lumen ◽  
Starch Digestion ◽  
Proximal Small Intestine ◽  
Digestion Kinetics ◽  
High Amylose

AbstractThis study aimed to examine in vivo starch digestion kinetics and to unravel the mechanisms of starch hydrolysing enzymes. Ninety pigs (23 (sd 2·1) kg body weight) were assigned to one of nine treatments in a 3×3 factorial arrangement, with starch source (barley, maize, high-amylose (HA) maize) and form (isolated, within cereal matrix, extruded) as factors. We determined starch digestion coefficients (DC), starch breakdown products and digesta retention times in four small-intestinal segments (SI1–4). Starch digestion in SI2 of pigs fed barley and maize, exceeded starch digestion of pigs fed HA maize by 0·20–0·33 DC units (P<0·01). In SI3–4, barley starch were completely digested, whereas the cereal matrix of maize hampered digestion and generated 16 % resistant starch in the small intestine (P<0·001). Extrusion increased the DC of maize and HA maize starch throughout the small intestine but not that of barley (P<0·05). Up to 25 % of starch residuals in the proximal small intestine of pigs was present as glucose and soluble α(1–4) maltodextrins. The high abundance of glucose, maltose and maltotriose in the proximal small intestine indicates activity of brush-border enzymes in the intestinal lumen, which is exceeded by α-amylase activity. Furthermore, we found that in vivo starch digestion exceeded our in vitro predictions for rapidly digested starch, which indicates that the role of the stomach on starch digestion is currently underestimated. Consequently, in vivo glucose release of slowly digestible starch is less gradual than expected, which challenges the prediction quality of the in vitro assay.

Absorption from different intestinal segments during exercise

1997 ◽  
Vol 83 (1) ◽  
pp. 204-212 ◽  
Author(s):  
G. P. Lambert ◽  
R. T. Chang ◽  
T. Xia ◽  
R. W. Summers ◽  
C. V. Gisolfi
Keyword(s):  
Small Intestine ◽  
Intestinal Absorption ◽  
Water Flux ◽  
Test Solution ◽  
Solute Flux ◽  
Solution Composition ◽  
Cycle Exercise ◽  
Percent Change ◽  
Proximal Small Intestine ◽  
Intestinal Segments

Lambert, G. P., R. T. Chang, T. Xia, R. W. Summers, and C. V. Gisolfi. Absorption from different intestinal segments during exercise. J. Appl. Physiol. 83(1): 204–212, 1997.—This study evaluated intestinal absorption from the first 75 cm of the proximal small intestine during 85 min of cycle exercise [63.6 ± 0.7% peak O2 consumption (V˙o 2 peak)] while subjects ingested either an isotonic carbohydrate-electrolyte beverage (CHO-E) or a water placebo (WP). The CHO-E beverage contained 117 mM (4%) sucrose, 111 mM (2%) glucose, 18 meq Na+, and 3 meq K+. The two experiments were performed a week apart by seven subjects (6 men and 1 woman; meanV˙o 2 peak = 53.5 ± 6.5 ml ⋅ kg−1 ⋅ min−1). Nasogastric and multilumen tubes were fluoroscopically positioned in the gastric antrum and duodenojejunum, respectively. Subjects ingested 23 ml/kg body weight of the test solution, 20% (383 ± 11 ml) of this volume 5 min before exercise and 10% (191 ± 5 ml) every 10 min thereafter. By using the rate of gastric emptying (18.1 ± 1.1 vs. 19.2 ± 0.7 ml/min for WP and CHO-E, respectively) as the rate of intestinal perfusion, intestinal absorption was determined by segmental perfusion from the duodenum (0–25 cm) and jejunum (25–50 and 50–75 cm). Water flux was different ( P < 0.05) between solutions in the 0- to 25- and 25- to 50-cm segments for WP vs. CHO-E (30.7 ± 2.7 vs. 15.0 ± 2.9 and 3.8 ± 1.1 vs. 11.9 ± 3.3 ml ⋅ cm−1 ⋅ h−1, respectively). Furthermore, water flux differed ( P < 0.05) for WP in a comparison of the 0- to 25- to the 25- to 50-cm segment. Total solute flux (TSF) was not significantly different among segments for a given solution or between solutions for a given segment. There was no difference between trials for percent change in plasma volume. These results indicate that 1) fluid absorption in the proximal small intestine depends on the segment studied and 2) solution composition can significantly effect water absorption rate in different intestinal segments.

scholarly journals Giardia colonizes and encysts in high density foci in the murine small intestine

2016 ◽  
Author(s):  
NR Barash ◽  
C Nosala ◽  
JK Pham ◽  
SG Mclnally ◽  
S Gourguechon ◽  
...  
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Diarrheal Disease ◽  
Laboratory Culture ◽  
High Density ◽  
Infection Dynamics ◽  
Proximal Small Intestine ◽  
Entire Duration ◽  
Duration Of Infection

AbstractGiardiais a highly prevalent, yet understudied protistan parasite causing diarrheal disease worldwide. Hosts ingestGiardiacysts from contaminated sources. In the gastrointestinal tract, cysts excyst to become motile trophozoites, colonizing and attaching to the gut epithelium. Trophozoites later differentiate into infectious cysts that are excreted and contaminate the environment. Due to the limited accessibility of the gut, the temporospatial dynamics of giardiasis in the host is largely inferred from laboratory culture and thus may not mirrorGiardiaphysiology in the host. Here we have developed bioluminescent imaging (BLI) to directly interrogate and quantify thein vivotemporospatial dynamics of giardiasis, thereby providing an improved murine model to evaluate anti-Giardiadrugs. Using BLI, we determined that parasites primarily colonize the proximal small intestine non-uniformly in high-density foci. By imaging encystation-specific bioreporters, we show that encystation initiates shortly after inoculation and continues throughout the entire duration of infection. Encystation also initiates in high-density foci in the proximal small intestine, and high-density laboratory cultures of parasites are also stimulated to encyst. This work overturns the assumption that parasites encyst later during infection as they are dislodged and travel through the colon. We suggest that these high-density regions of parasite colonization likely result in localized pathology to the epithelium, and encystation occurs when trophozoites reach a threshold density due to local nutrient depletion. This more accurate visualization of giardiasis redefines the dynamics ofin vivo Giardialife cycle, paving the way for future mechanistic studies of density-dependent parasitic processes in the host.SignificanceGiardiais a single-celled parasite causing both acute and chronic diarrheal disease in over one billion people worldwide. Due to limited access to the site of infection in the gastrointestinal tract, our understanding of the dynamics ofGiardiainfections in the host has remained limited, and largely inferred from laboratory culture. To better understand giardiasis in the host, we developed imaging methods to quantifyGiardiaexpressing bioluminescent physiological reporters in live mice. We discovered that parasites primarily colonize and encyst in the proximal small intestine in discrete, high-density foci. Furthermore, this work provides evidence of a parasite density-based threshold for the differentiation ofGiardiainto cysts in the host. These findings overturn existing paradigms of giardiasis infection dynamics in the host.

Sites of Maximal Absorption and Hydrolysis of Two Dipeptides by Rat Small Intestine in Vivo

1973 ◽  
Vol 44 (6) ◽  
pp. 583-594 ◽  
Author(s):  
R. F. Crampton ◽  
Maria T. Lis ◽  
D. M. Matthews
Keyword(s):  
Amino Acids ◽  
Small Intestine ◽  
Intestinal Lumen ◽  
Proximal Half ◽  
Proximal Small Intestine ◽  
Significant Difference ◽  
Maximal Absorption ◽  
Hydrolysis Of ◽  
Mucosal Uptake

1. Though mucosal uptake of peptides plays an important part in protein absorption, little is known about the site of maximal absorption of peptides in the small intestine. This paper reports an investigation of the characteristics of absorption and hydrolysis of l-methionyl-l-methionine (Met-Met) and glycylglycine (Gly-Gly) by tied loops along the length of the small intestine of the rat, and those of absorption of the equivalent l-methionine (Met) and glycine (Gly). 2. Absorption of Met-Met, or a mixture of Met-Met and Met, was maximal in the proximal half of the small intestine, whereas absorption of Met was maximal in the distal half. Absorption of Met-Met was greater than that of the equivalent Met, especially in the proximal small intestine. In most sites, absorption of a mixture of Met-Met and Met was not significantly different from that of the equivalent Met-Met. Absorption of Met was not increased by raising its concentration from 100 to 200 μmol/ml, but addition of Met-Met (50 μmol/ml) produced a large increase in absorption, indicating that absorption of Met from Met-Met is independent of that from free Met. During absorption of Met-Met, large amounts of free Met appeared in the intestinal lumen. Most of this resulted from intralumen hydrolysis. The hydrolytic ability of mucosal homogenates was several times greater than that required to hydrolyse the Met-Met disappearing from the lumen during absorption. 3. The sites of maximal absorption of Gly-Gly, Gly and a mixture of Gly-Gly and Gly, were all in the proximal half of the intestine near the mid-point. Absorption of Gly-Gly was greater than that of the equivalent Gly, especially in the proximal sites. In several sites, there was no significant difference between absorption of a mixture of Gly-Gly and Gly and that of the equivalent Gly-Gly. During absorption of Gly-Gly, the amounts of free Gly appearing in the lumen were small except in the two most distal sites. Most of the free Gly resulted from back-diffusion from the mucosa. The hydrolytic ability of mucosal homogenates was barely adequate to hydrolyse the Gly-Gly disappearing from the lumen during absorption. 4. The results suggest that there is no real discrepancy between the site of maximal absorption of protein digestion products from tied loops of small intestine and that of their absorption in the intact animal. They indicate that absorption of Met and Met-Met involves independent mechanisms, and confirm previous evidence that the capacity of the intestine to absorb mixtures of peptides and amino acids is greater than its capacity to absorb amino acids alone.

scholarly journals Giardia Colonizes and Encysts in High-Density Foci in the Murine Small Intestine

mSphere ◽  
2017 ◽  
Vol 2 (3) ◽  
Author(s):  
N. R. Barash ◽  
C. Nosala ◽  
J. K. Pham ◽  
S. G. McInally ◽  
S. Gourguechon ◽  
...  
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Animal Models ◽  
Diarrheal Disease ◽  
Laboratory Culture ◽  
High Density ◽  
Proximal Small Intestine ◽  
High Parasite Density ◽  
High Parasite

ABSTRACT Giardia is a single-celled parasite causing significant diarrheal disease in several hundred million people worldwide. Due to limited access to the site of infection in the gastrointestinal tract, our understanding of the dynamics of Giardia infections in the host has remained limited and largely inferred from laboratory culture. To better understand Giardia physiology and colonization in the host, we developed imaging methods to quantify Giardia expressing bioluminescent physiological reporters in two relevant animal models. We discovered that parasites primarily colonize and encyst in the proximal small intestine in discrete, high-density foci. We also show that high parasite density contributes to encystation initiation. Giardia lamblia is a highly prevalent yet understudied protistan parasite causing significant diarrheal disease worldwide. Hosts ingest Giardia cysts from contaminated sources. In the gastrointestinal tract, cysts excyst to become motile trophozoites, colonizing and attaching to the gut epithelium. Trophozoites later differentiate into infectious cysts that are excreted and contaminate the environment. Due to the limited accessibility of the gut, the temporospatial dynamics of giardiasis in the host are largely inferred from laboratory culture and thus may not mirror Giardia physiology in the host. Here, we have developed bioluminescent imaging (BLI) to directly interrogate and quantify the in vivo temporospatial dynamics of Giardia infection, thereby providing an improved murine model to evaluate anti-Giardia drugs. Using BLI, we determined that parasites primarily colonize the proximal small intestine nonuniformly in high-density foci. By imaging encystation-specific bioreporters, we show that encystation initiates shortly after inoculation and continues throughout the duration of infection. Encystation also initiates in high-density foci in the proximal small intestine, and high density contributes to the initiation of encystation in laboratory culture. We suggest that these high-density in vivo foci of colonizing and encysting Giardia likely result in localized disruption to the epithelium. This more accurate visualization of giardiasis redefines the dynamics of the in vivo Giardia life cycle, paving the way for future mechanistic studies of density-dependent parasitic processes in the host. IMPORTANCE Giardia is a single-celled parasite causing significant diarrheal disease in several hundred million people worldwide. Due to limited access to the site of infection in the gastrointestinal tract, our understanding of the dynamics of Giardia infections in the host has remained limited and largely inferred from laboratory culture. To better understand Giardia physiology and colonization in the host, we developed imaging methods to quantify Giardia expressing bioluminescent physiological reporters in two relevant animal models. We discovered that parasites primarily colonize and encyst in the proximal small intestine in discrete, high-density foci. We also show that high parasite density contributes to encystation initiation.

scholarly journals Application of selective extraction to the study of iron species present in diet and rat gastrointestinal tract contents

1992 ◽  
Vol 67 (3) ◽  
pp. 437-444 ◽  
Author(s):  
Robert J. Simpson ◽  
Sanjiv Sidhar ◽  
Timothy J. Peters
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Stomach Contents ◽  
Selective Extraction ◽  
Proximal Small Intestine ◽  
Exchangeable Fraction ◽  
Fe Speciation ◽  
Pelleted Diet

Iron speciation in rodent diet and rat gastrointestinal tract lumen during dietary digestion and absorption was investigated with a novel selective extraction technique. Five Fe fractions were identified, namely exchangeable (soluble in 1 M-magnesium chloride), carbonate-bound (soluble in mild acid), oxide-bound (soluble in hydroxylamine–acetic acid), organic-bound (soluble after treatment with peroxide in nitric acid) and residual. Fe from the pelleted diet was mobilized by rat stomach to the exchangeable fraction, then redistributed to the carbonate- and oxide-bound fractions on passage through the proximal small intestine. In vitro incubation of diet with hydrochloric acid failed to mimic the in vivo effect of the stomach. In vitro neutralization of stomach contents with bicarbonate was found to produce a similar effect on Fe speciation to that seen when diet passed the proximal small intestine in vivo. Comparison of59Fe speciation in extrinsically labelled diet with endogenous Fe speciation showed that extrinsic labelling does not uniformly label all endogenous species. The experiments suggest that selective extraction may provide a useful approach to the study of Fe species present in diets, in vitro digestions and gastrointestinal contents.

A Clinical Single-Pass Perfusion Investigation of the Dynamic in Vivo Secretory Response to a Dietary Meal in Human Proximal Small Intestine

2006 ◽  
Vol 23 (4) ◽  
pp. 742-751 ◽  
Author(s):  
Eva M. Persson ◽  
Ralf G. Nilsson ◽  
Göran I. Hansson ◽  
Lars J. Löfgren ◽  
Fredrik Libäck ◽  
...  
Keyword(s):  
Small Intestine ◽  
Secretory Response ◽  
Single Pass ◽  
Pass Perfusion ◽  
Proximal Small Intestine

scholarly journals Pathology of Infestation of the Rat With Nippostrongylus Muris (Yokogawa) III. Jejunal Fluxes in Vivo of Water, Sodium, and Chloride

1960 ◽  
Vol 13 (2) ◽  
pp. 171 ◽  
Author(s):  
LEA Symons
Keyword(s):  
Small Intestine ◽  
Hypertonic Saline ◽  
Isotonic Saline ◽  
Mucosal Tissue ◽  
Unidirectional Fluxes ◽  
Saline Solutions ◽  
Net Fluxes ◽  
Infested Animal

The net fluxes of water, sodium, and chloride were measured in vivo by perfusion of the jejunum. There was a net absorption of these three substances from isotonic saline solutions in normal rats, but a net influx to the lumen in each instance in rats infested with the nematode Nippo8trongylu8 muri8. The unidirectional fluxes of sodium and the net fluxes during perfusion with hypo- and hypertonic saline solutions indicated that this was fundamentally due to a derangement of efflux while influx was unaffected. The gross effect, however, was also due to an increase of influx because of the greater weight of mucosal tissue per centimetre of jejunum in the infested animal. The unidirectional fluxes of water did not support these conclusions unequivocally. The fluid which accumulates in the infested� small intestine can be explained by these results.

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