Fluid Movement Across the Wall of the Small Intestine in Vitro

1956 ◽  
Vol 187 (2) ◽  
pp. 244-246 ◽  
Author(s):  
T. Hastings Wilson
Keyword(s):  
Small Intestine ◽  
Sodium Chloride ◽  
Saline Solution ◽  
Isotonic Saline ◽  
Bicarbonate Secretion ◽  
Serosal Side ◽  
Fluid Movement ◽  
Mucosal Side

Small sacs of everted jejunum of the hamster were incubated in sugar free bicarbonate-saline solution in vitro. Both fluid and sodium chloride moved across the wall of the intestine from mucosal to serosal side. This movement of isotonic saline solution across the intestine was inhibited anaerobically. A small bicarbonate secretion was noted in the direction of serosal to mucosal side.

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

1963 ◽  
Vol 204 (1) ◽  
pp. 105-108 ◽  
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.

scholarly journals Absorption and metabolism of volatile fatty acids by rumen and omasum

2012 ◽  
Vol 36 (1) ◽  
pp. 93-99 ◽  
Author(s):  
João Luiz Pratti Daniel ◽  
João Chrysostomo de Resende Júnior
Keyword(s):  
Fatty Acids ◽  
Mitotic Index ◽  
Volatile Fatty Acids ◽  
Diffusion Chamber ◽  
Serosal Side ◽  
Buffer Solution ◽  
Mucosal Side ◽  
Over Time ◽  
Fractional Absorption

Volatile fatty acids (VFA) absorption and metabolic capacity of rumen and omasum were compared, in vitro. Fragments of rumen wall and omasum laminae were taken from eight adult crossbred bovines. An isolated fragment of the mucosa was fitted in a tissue diffusion chamber. Valeric acid and CrEDTA were added to ruminal fluid and placed on the mucosal side and buffer solution was placed on the serosal side. Fractional absorption rates were measured by exponential VFA:Cr ratio decay over time. Metabolism rate was determined as the difference between VFA absorbed and VFA which appeared on the serosal side over time. Mitotic index was higher in omasum (0.52%) than in rumen epithelium (0.28%). VFA fractional absorption rate was higher in omasum (4.6%/h.cm²) than in rumen (0.4%/h.cm²). Acetate, propionate, butyrate, and valerate showed similar fractional absorption rates in both fragments. Percentage of metabolized acetate and propionate was lower than butyrate and valerate in both stomach compartments. In the rumen, individual VFA metabolism rates were similar (mean of 7.7 , but in the omasum, valerate (90.0 was more metabolized than butyrate (59.6 propionate (69.8 and acetate (51.7 . Correlation between VFA metabolism and mitotic index was positive in the rumen and in the omasum. In conclusion, VFA metabolism and absorption potential per surface of the omasum is higher than that of the rumen. Variations on rumen and omasum absorption capacities occur in the same way, and there are indications that factors capable of stimulating rumen wall proliferation are similarly capable of stimulating omasum walls.

scholarly journals Amino acids and carbohydrates absorption by Na+-dependent transporters in the pyloric ceca of Hoplias malabaricus (Erythrinidae)

2001 ◽  
Vol 31 (5) ◽  
pp. 793-797 ◽  
Author(s):  
Vania Lucia Pimentel Vieira ◽  
Bernardo Baldisserotto
Keyword(s):  
Amino Acids ◽  
Optimal Growth ◽  
Serosal Side ◽  
Carbohydrate Absorption ◽  
Hoplias Malabaricus ◽  
Main Site ◽  
Adequate Diet ◽  
Mucosal Side ◽  
Pyloric Ceca

Information about amino acids and carbohydrate absorption in fish is important to formulate an adequate diet to obtain optimal growth. Therefore, the objective of this study was to investigate if Na+-dependent transporters are involved on the absorption of glycine, L-glutamine, L-leucine, L-lysine, L-proline, L-alanine, and the carbohydrates fructose and glucose in the pyloric ceca of Hoplias malabaricus. The pyloric ceca were mounted in a system of continuous perfusion "in vitro". Amino acids and carbohydrates were placed on the mucosal side at concentrations of 10, 20, and 40mM. The serosal side of the pyloric ceca was positive in relation to the mucosal side. The addition of glycine, L-glutamine, L-leucine, L-lysine, L-proline (all tested concentrations), and glucose (at concentrations of 20 and 40mM) increased the positivity of the serosal side, indicating the presence of Na+-dependent transporters in the absorption of these substances. L-alanine and fructose did not change the positivity of the serosal side. The pyloric ceca seem to be the main site of nutrient absorption in the digestive tract of H. malabaricus.

Avian cecum: role of glucose and volatile fatty acids in transepithelial ion transport

1991 ◽  
Vol 260 (5) ◽  
pp. G703-G710 ◽  
Author(s):  
B. R. Grubb
Keyword(s):  
Fatty Acids ◽  
Ion Transport ◽  
Volatile Fatty Acids ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Serosal Side ◽  
Na Transport ◽  
Cl Secretion ◽  
Mucosal Side

In the fowl cecum in vitro, the influence of glucose and the three most prevalent naturally occurring volatile fatty acids (acetate, propionate, butyrate) on short-circuit current (Isc), electrical resistance, and transport of Na and Cl was determined. When glucose, acetate, or butyrate was present, ion transport was characterized by electrogenic Na absorption, greater than 65% of which was amiloride inhibitable, and Cl secretion, which also was electrogenic. Isc could be completely accounted for by net fluxes of Na and Cl. When glucose, acetate, or butyrate (10 mM both sides) was included in the incubation medium, cecal tissue maintained its Isc and a constant rate of net Na absorption and Cl secretion for a 5-h period. When no substrate was present or propionate was included in the medium, a marked fall in Isc and net Na and Cl fluxes was seen. Glucose caused an increase in Isc when added only to the serosal side. As 3-O-methylglucose (not metabolized) was not effective in stimulating Isc of the cecum (serosal or mucosal addition), it appeared that glucose increased Isc by acting as an energy substrate for active Na transport. Acetate and butyrate appeared to be equally effective in stimulating Na transport and Isc when placed on either side of the membrane. When the preparation was supplied with glucose (serosal side) and acetate was added to the mucosal side, no further stimulation of Isc occurred. Thus it appeared that acetate and butyrate were acting as substrates for active Na transport rather than stimulating Na transport by some other mechanism such as a cotransport with Na.(ABSTRACT TRUNCATED AT 250 WORDS)

Investigation of Mechanism of Diuresis Produced in the Rat by an Intravenous Infusion of Isotonic Solution of Sodium Chloride

1958 ◽  
Vol 195 (1) ◽  
pp. 137-141 ◽  
Author(s):  
R. Keeler ◽  
H. Schnieden
Keyword(s):  
Sodium Chloride ◽  
Plasma Volume ◽  
Intravenous Infusion ◽  
Plasma Proteins ◽  
Saline Solution ◽  
Isotonic Saline ◽  
Plasma Volume Expansion ◽  
Bilateral Vagotomy ◽  
Diuretic Response ◽  
Slight Rise

Following intravenous infusions of isotonic saline a marked increase in the tubular rejection fractions for sodium and water occurred. Only a slight rise in inulin clearance was found. Since the expansion of plasma volume produced by 6% albumin in isotonic saline solution was less effective in producing a diuresis than a similar expansion of plasma volume by an infusion of isotonic saline the results suggest that plasma volume expansion alone could not account for all the effects observed in saline diuresis. Dilution of plasma proteins may have played some part but bilateral vagotomy or bilateral severance of the cervical cardiac branches of the vagus did not significantly affect the diuretic response to an intravenous infusion of 0.9% sodium chloride solution.

Prolylhydroxyproline Absorption in Hamsters

1972 ◽  
Vol 50 (7) ◽  
pp. 782-790 ◽  
Author(s):  
H. J. Hueckel ◽  
Q. R. Rogers
Keyword(s):  
Small Intestine ◽  
Absorption Rate ◽  
Intestinal Transport ◽  
Intestinal Wall ◽  
Relative Resistance ◽  
Rate Of Absorption ◽  
Small Intestines ◽  
Mucosal Side ◽  
Active Reabsorption

The intestinal transport of the dipeptide prolylhydroxyproline was investigated using hamsters and segments of hamster small intestines. The feeding of prolylhydroxyproline to hamsters resulted in the urinary excretion of 2% of the ingested dipeptide after 3 h or 7% after 24 h. In vitro perfusions of prolylhydroxyproline through the hamster small intestine resulted in the movement of the dipeptide across the intestinal wall. The rate of absorption was proportional to the concentration of prolylhydroxyproline on the mucosal side (0.17 μmol Pro∙Hyp/mM in lumen/g tissue/h). Anoxia, 2,4-dinitrophenol, cyanide, or an excess of proline or hydroxyproline did not change this absorption rate. These results suggest that prolylhydroxyproline is absorbed by "simple passive diffusion", that it reaches the site of intestinal absorption because of its relative resistance to enzymatic hydrolysis, and that it is excreted by glomerular filtration without subsequent active reabsorption.

Intestinal transport of l-tryptophan in vitro: inhibition by high concentrations

1960 ◽  
Vol 199 (6) ◽  
pp. 1033-1036 ◽  
Author(s):  
Richard P. Spencer ◽  
A. H. Samiy
Keyword(s):  
Amino Acids ◽  
Small Intestine ◽  
Aromatic Amino Acids ◽  
Intestinal Transport ◽  
Serosal Side ◽  
Mutual Inhibition ◽  
High Concentrations ◽  
Two Sides ◽  
Bathing Fluid

At a concentration of 5 x 10–3 m, everted hamster intestinal sacs showed net transport of l-tryptophan from the mucosal to the serosal side, when the concentration was initially equal on the two sides. Thus, l-tryptophan is not an exception to the generalization that such intestinal preparations transport monoamino-monocarboxylic amino acids against a concentration gradient. High concentrations of l-tryptophan inhibit such transport. This may account for previous failure by others to observe l-tryptophan transport against a gradient at an initial concentration of 20 x 10–3 m. Transport of l-tryptophan was greater by sacs from the middle of the small intestine than by those from the ends (this has been previously reported for l-phenylalanine and l-tyrosine). On the basis of this observation and those of mutual inhibition of transport, it is likely that the four aromatic amino acids share at least one common step in their intestinal absorption. Segments of hamster small intestine have been shown to accumulate l-tryptophan, developing a concentration greater than that of the bathing fluid.

Characteristics of luminal bicarbonate secretion by rat cecum in vitro

1991 ◽  
Vol 260 (3) ◽  
pp. G464-G470 ◽  
Author(s):  
P. Canfield
Keyword(s):  
Proton Pump Inhibitor ◽  
Proton Pump ◽  
Bicarbonate Secretion ◽  
Hepes Buffer ◽  
Set Up ◽  
Mucosal Side ◽  
Rat Cecum

Under in vitro conditions the rat cecum transported HCO3- from the serosal to an unbuffered solution in contact with the mucosal side [Js----m = 7.12 +/- 0.18 mumol.cm-2.h-1 (n = 149)]. With reversed tissues, a significantly lower flux was obtained [Jm----s = 2.47 +/- 0.11 mumol.cm-2.h-1 (n = 42)]. Both fluxes were stable for several hours. Increasing the H+ gradient across the tissue for 60 min did not change either flux. Anoxia for 45 min reversibly reduced Js----m by 65 +/- 3% (n = 20) but had no effect on Jm----s. Both fluxes were linearly related to HCO3- concentration on the buffered side, but the slope for Js----m was 3.5 times that for Jm----s. When tissues were initially set up in HEPES buffer rather than HCO3-, Js----m was 0.12 +/- 0.05 mumol.cm-2.h-1 (n = 6), which is not significantly different from zero. Replacement of Na+ by choline reduced Js----m by 40 +/- 3% (n = 11) and ouabain (1 mM) by 24 +/- 3% (n = 5). Replacement of Cl- with isethionate or K+ with Na+ for 60 min did not alter Js----m. Serosal application of DIDS (0.5 mM) reduced Js----m by 24 +/- 6% (n = 6), but SITS (0.5 mM), furosemide (1 mM), acetazolamide (0.1 mM), amiloride (1 mM), and a proton pump inhibitor (Sch 28080, 50 microM) had no effect. Mucosal application of DIDS, furosemide, and amiloride had no effect on Js----m. Serosal tetrodotoxin (1 microM) and indomethacin (28 microM) were also without effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Active transport of C14-d-glucose by turtle small intestine

1961 ◽  
Vol 201 (2) ◽  
pp. 295-297 ◽  
Author(s):  
Sister Alice Marie Fox
Keyword(s):  
Small Intestine ◽  
Active Transport ◽  
Intestinal Transport ◽  
Intestinal Wall ◽  
Chrysemys Picta ◽  
Tissue Analysis ◽  
Serosal Side ◽  
Concentration Difference ◽  
Apparent Concentration

An in vitro preparation was used to demonstrate that C14-d-glucose is taken up at the mucosal surface of turtle small intestine at 30 C. Movement of the sugar across the intestinal tissues and its release into the serosal fluid against an apparent concentration difference was shown. The source of the sugar entering the medium on the serosal side appeared to be, in part, the glucose taken up from the mucosal fluid, and, in part, some stored carbohydrate. Tissue analysis indicated the presence of a glycogenlike polysaccharide in the intestinal wall of both active and cold-torpid turtles. It was concluded that, during intestinal transport in Chrysemys picta, some of the glucose absorbed is converted to endogenous carbohydrate, or metabolized, and some is translocated.

On the Mechanism of Isosmotic Transport Across the Small Intestine. The Composition of the Absorbate Transported from a Mucosal Solution made Hypertonic by the Addition of Mannitol

1973 ◽  
Vol 51 (2) ◽  
pp. 130-138 ◽  
Author(s):  
P. K. Dinda ◽  
Marjorie Beck ◽  
I. T. Beck
Keyword(s):  
Small Intestine ◽  
Solute Transport ◽  
Fluid Transport ◽  
Linear Increase ◽  
Mucosal Surface ◽  
Bathing Solution ◽  
Serosal Side ◽  
Hypertonic Solutions ◽  
Mucosal Side

Experiments were performed to investigate the mechanism by which the fluid transported across the small intestine becomes isosmotic with the mucosal solution when the latter is made hypertonic by the addition of a poorly absorbed substance. The mid small intestine of the hamster was isolated and everted. The mucosal surface of the control preparation was bathed with an isotonic Krebs–Ringer bicarbonate solution containing 10 mM glucose (KRBSG) (292 mOsmol/kg). The mucosal surface of the experimental preparations was bathed with one of the hypertonic solutions. These hypertonic solutions were prepared by the addition of 1, 50, 100, or 150 mM mannitol to KRBSG. No bathing solution was placed on the serosal side of these preparations, so that the fluid transported across the intestine, undiluted by a bathing solution (absorbate), could be collected on the serosal side. Results show that the absorbate was always isosmotic with the mucosal solution. In the experimental preparations, as compared to the absorption of other solutes, mannitol was poorly absorbed, even though its concentration in the absorbate sometimes reached 35% of its concentration in the mucosal solution. The small amount of mannitol found in the absorbate was never sufficient to render the absorbates isosmotic with hypertonic mucosal solutions. The absorbate became isosmotic with the mucosal solution due to an increased concentration of other solutes transported from the mucosal side. Increasing the osmolality of the mucosal solution progressively from 292 to 442 mOsmol/kg caused a linear increase in the concentration of Na, K, glucose, and mannitol in the absorbate, but, except for mannitol, the net amount of these substances transported (per gram dry tissue) to the serosal side decreased linearly. The transport of fluid also decreased. Our data further indicate that the ratio of fluid and solute transport progressively decreased with the increase in osmolality of the mucosal solution. Therefore, it appears that when the mucosal solution is made hypertonic by the addition of a poorly absorbed substance, the absorbate becomes isosmotic with the hypertonic mucosal solution by means of a greater diminution of fluid transport than of solute transport.

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