THE EFFECT OF FLOW RATE AND OSMOLARITY OF LUMEN CONTENTS ON CALCIUM AND WATER ABSORPTION FROM THIRY-VELLA FISTULAS IN DOGS

1963 ◽  
Vol 41 (1) ◽  
pp. 127-130 ◽  
Author(s):  
Carl F. Cramer ◽  
Tennyson A. Haqq
Keyword(s):  
Water Absorption ◽  
Absorptive Capacity ◽  
Calcium Absorption ◽  
Sodium Concentration ◽  
Jejunal Loop ◽  
Number Of Factors ◽  
Normal Absorption ◽  
Rate Of Absorption ◽  
Static Conditions

The effect of a number of factors which locally might affect intestinal absorption of calcium in vivo was studied. Changes of osmolarity or of sodium concentration altered neither the calcium absorption rate nor the maximal absorptive capacity found at higher calcium concentrations. Under static conditions in a healed jejunal loop, calcium was absorbed more rapidly at first, but after 40 minutes the rate of absorption was essentially constant. Water absorption was approximately constant throughout the 2 hours. On the other hand, when the solutions flowed slowly through the gut loop, calcium was absorbed six times, and water four times more rapidly. The importance of these findings to normal absorption is discussed.

THE EFFECT OF FLOW RATE AND OSMOLARITY OF LUMEN CONTENTS ON CALCIUM AND WATER ABSORPTION FROM THIRY-VELLA FISTULAS IN DOGS

1963 ◽  
Vol 41 (1) ◽  
pp. 127-130 ◽  
Author(s):  
Carl F. Cramer ◽  
Tennyson A. Haqq
Keyword(s):  
Water Absorption ◽  
Absorptive Capacity ◽  
Calcium Absorption ◽  
Sodium Concentration ◽  
Jejunal Loop ◽  
Number Of Factors ◽  
Normal Absorption ◽  
Rate Of Absorption ◽  
Static Conditions

The effect of a number of factors which locally might affect intestinal absorption of calcium in vivo was studied. Changes of osmolarity or of sodium concentration altered neither the calcium absorption rate nor the maximal absorptive capacity found at higher calcium concentrations. Under static conditions in a healed jejunal loop, calcium was absorbed more rapidly at first, but after 40 minutes the rate of absorption was essentially constant. Water absorption was approximately constant throughout the 2 hours. On the other hand, when the solutions flowed slowly through the gut loop, calcium was absorbed six times, and water four times more rapidly. The importance of these findings to normal absorption is discussed.

Intestinal calcium absorption: differences in transport between duodenum and ileum

1976 ◽  
Vol 230 (5) ◽  
pp. 1255-1260 ◽  
Author(s):  
J Behar ◽  
MD Kerstein
Keyword(s):  
Vitamin D ◽  
Water Absorption ◽  
Osmotic Pressure ◽  
Calcium Absorption ◽  
Choline Chloride ◽  
Strong Association ◽  
Solvent Drag ◽  
Experimental Conditions

The interaction of calcium with sugar, sodium, and water absorption was studied in rats fed laboratory chow and in vitamin D-deficient and -repleted rats with the use of intestinal loops in vivo. Calcium absorption in the duodenum was enhanced by D-glucose only in the vitamin D-deficient state. In both vitamin D-deficient and -repleted ileum, calcium absorption decreased when NaCl was replaced by mannitol; however, it remained unchanged when NaCl was replaced by choline chloride or urea. Calcium absorption was enhanced by actively transported sugars and by increasing net water flow generated by differences in osmotic pressure and urea. Under all experimental conditions there was a strong association between net water and calcium absorption in the ileum. These findings suggest that calcium absorption is enhanced by solvent drag, although the role of sodium cannot be excluded entirely.

scholarly journals Acute in vivo studies on glucose absorption from the small intestine of lambs, sheep and rats

1971 ◽  
Vol 25 (1) ◽  
pp. 57-76 ◽  
Author(s):  
R. G. White ◽  
V. J. Williams ◽  
R. J. H. Morris
Keyword(s):  
Body Weight ◽  
Small Intestine ◽  
Absorptive Capacity ◽  
Glucose Absorption ◽  
In Vivo Studies ◽  
Adult Sheep ◽  
Young Rats ◽  
Unit Body Weight ◽  
Rate Of Absorption

1. Rates of disappearance of glucose from ligated loops of small intestine in lambs, adult sheep and young rats were studied. The concentration of glucose in the lumen decreased exponentially with time, suggesting that within a range of concentrations of 166–277 m-moles/l glucose was absorbed mainly by passive diffusion.2. The rate of absorption of glucose from a 166 mM-solution based on either zero or first order kinetics and expressed as m-moles/m small intestine per h decreased along the intestine from the duodenum to the ileum in lambs and rats. The decrease was slight in adult sheep.3. The total absorptive capacity of the small intestine of adult grazing sheep for glucose from 166 mM-solutions (06 m-moles/kg body-weight per h) was approximately 25% of that for lambs less than 1 week of age.4. Young rats had a greater absorptive capacity of the small intestine (12.9m-moles/kg body-weight per h) than adult sheep of about 40 kg body-weight (0.6 m-moles/kg body-weight per h) and this largely reflected a longer small intestine per unit body-weight.5. The absorptive capacity of lambs for glucose was greater when the level of voluntary lactose intake was increased before an experiment. The absorptive capacity of the ileum of adult sheep given wheat was greater than that of grazing adult sheep.6. Developmental changes in glucose absorption are discussed in relation to normal changes in diet and to changes in the morphology of the small intestine with age.

Acute effects of prolactin on passive calcium absorption in the small intestine by in vivo perfusion technique

1998 ◽  
Vol 76 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Nateetip Krishnamra ◽  
Yinglak Wirunrattanakij ◽  
Liangchai Limlomwongse
Keyword(s):  
Body Weight ◽  
Calcium Absorption ◽  
Dry Weight ◽  
Sodium Concentration ◽  
Plasma Calcium ◽  
Calcium Flux ◽  
Proximal Jejunum ◽  
Perfusion Technique ◽  
Calcium Fluxes

The acute effect of intraperitoneally administered prolactin (0.2, 0.4, and 0.6 mg/kg body weight) on passive calcium transport in duodenum, proximal jejunum, and ileum of sexually mature female Wistar rats was investigated by using an in vivo perfusion technique. Test solution containing (in mM) NaCl, 100; KCl, 4.7; MgSO4, 1.2; CaCl2, 20; D-glucose, 11; sodium ferrocyanide (Na4Fe(CN)6), an index of net water transport, 20; and 0.7 µCi 45CaCl2 (1 Ci = 37 GBq) was perfused through the 10-cm intestinal loop for 60 min. Results showed that 0.4 mg prolactin/kg body weight significantly increased duodenal net Ca absorption (net Ca) from 23.81 ± 1.84 to 30.56 ± 1.57 mmol/g dry weight (p < 0.05) by stimulating the lumen to plasma calcium flux (CaL-P). The jejunum responded to 0.2, 0.4, and 0.6 mg prolactin/kg body weight by reversing from net Ca absorption of 18.60 ± 1.70 mmol/g dry weight to net secretion of -3.30 ± 1.56, -10.39 ± 2.21, and -11.79 ± 2.04 mmol/g dry weight (p < 0.01), respectively, as a result of a dose-dependent increase in plasma to lumen calcium flux (CaP-L). Calcium fluxes in the ileum on the other hand did not respond to prolactin. There was a close correlation between net water flux and net calcium flux in all three intestinal segments under basal condition regardless of the luminal sodium concentration. However, this correlation was lost after prolactin administration, which while having no effect on net water flux, altered the duodenal and jejunal calcium fluxes. By varying the luminal concentration of sodium, it was found that the stimulatory effect of 0.4 mg prolactin/kg body weight on the duodenal CaL-P was reduced when compared with control, i.e., 17.84 ± 0.91 vs. 26.64 ± 1.05 mmol/g dry weight at a sodium concentration of 180 mM, and 14.48 ± 0.99 vs. 20.12 ± 1.34 mmol/g dry weight at a sodium concentration of 140 mM. At a sodium concentration of 80 mM, the prolactin effect was absent. Since duodenal Na+-K+ ATPase activity was increased by prolactin from 3.77 ± 0.16 to 4.95 ± 0.30 µmol Pi ·mg-1 protein ·h-1 (p < 0.05), sodium dependency of the prolactin-enhanced lumen to plasma calcium flux may be related to both sodium-induced water flow and calcium-sodium exchange across the basolateral membrane. Thus, it was postulated that under basal condition, net calcium transport in the small intestine occurred with the sodium-induced water transport along the paracellular pathway. However, after prolactin administration, this association was lost. Prolactin-enhanced lumen to plasma calcium flux in the duodenum was sodium dependent and involved the Na+-K+ ATPase activity. In the proximal jejunum, prolactin stimulated plasma to lumen calcium flux, but the mechanism was not known.Key words: calcium absorption, calcium fluxes, Na-K ATPase, perfusion technique, prolactin.

Analysis of the Dynamics of the Electric Capacitance of a Cell Monolayer at the Late Stages of Caco-2 cell Differentiation

2019 ◽  
Vol 35 (6) ◽  
pp. 87-90
Author(s):  
S.V. Nikulin ◽  
V.A. Petrov ◽  
D.A. Sakharov
Keyword(s):  
Impedance Spectroscopy ◽  
Cell Monolayer ◽  
Microfluidic Chips ◽  
Russian Science ◽  
Electric Capacitance ◽  
A Cell ◽  
Static Conditions ◽  
Late Stages

The real-time monitoring of electric capacitance (impedance spectroscopy) allowed obtaining evidence that structures which look like intestinal villi can be formed during the cultivation under static conditions as well as during the cultivation in microfluidic chips. It was shown in this work via transcriptome analysis that the Hh signaling pathway is involved in the formation of villus-like structures in vitro, which was previously shown for their formation in vivo. impedance spectroscopy, intestine, villi, electric capacitance, Hh The study was funded by the Russian Science Foundation (Project 16-19-10597).

scholarly journals Sodium Radiofrequency Coils for Magnetic Resonance: From Design to Applications

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1788
Author(s):  
Giulio Giovannetti ◽  
Alessandra Flori ◽  
Nicola Martini ◽  
Roberto Francischello ◽  
Giovanni Donato Aquaro ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Sodium Concentration ◽  
Resonance Spectroscopy ◽  
Sodium Mri ◽  
Human Organs ◽  
Low Sodium ◽  
Radiofrequency Coils ◽  
Anatomical Imaging ◽  
Strong Gradient

Sodium (23Na) is the most abundant cation present in the human body and is involved in a large number of vital body functions. In the last few years, the interest in Sodium Magnetic Resonance Imaging (23Na MRI) has considerably increased for its relevance in physiological and physiopathological aspects. Indeed, sodium MRI offers the possibility to extend the anatomical imaging information by providing additional and complementary information on physiology and cellular metabolism with the heteronuclear Magnetic Resonance Spectroscopy (MRS). Constraints are the rapidly decaying of sodium signal, the sensitivity lack due to the low sodium concentration versus 1H-MRI induce scan times not clinically acceptable and it also constitutes a challenge for sodium MRI. With the available magnetic fields for clinical MRI scanners (1.5 T, 3 T, 7 T), and the hardware capabilities such as strong gradient strengths with high slew rates and new dedicated radiofrequency (RF) sodium coils, it is possible to reach reasonable measurement times (~10–15 min) with a resolution of a few millimeters, where it has already been applied in vivo in many human organs such as the brain, cartilage, kidneys, heart, as well as in muscle and the breast. In this work, we review the different geometries and setup of sodium coils described in the available literature for different in vivo applications in human organs with clinical MR scanners, by providing details of the design, modeling and construction of the coils.

Comparison of calcium absorptive and secretory capacities of segments of intact or functionally resected intestine during normo-, hypo-, and hyper-calcemia

1994 ◽  
Vol 72 (7) ◽  
pp. 764-770 ◽  
Author(s):  
N. Krishnamra ◽  
K. Angkanaporn ◽  
T. Deenoi
Keyword(s):  
Calcium Absorption ◽  
Intestinal Secretion ◽  
Proximal Colon ◽  
Plasma Calcium ◽  
Proximal Jejunum ◽  
Proximal Small Intestine ◽  
Enhanced Secretion ◽  
Rate Of Absorption ◽  
Plasma Calcium Concentration ◽  
Luminal Calcium

Absorptive and secretory capacities of six in situ intestinal loops of equal length were compared under the same calcium load and calcemic condition. The highest rate of calcium absorption was found in duodenum, colon, and proximal jejunum when loops were filled with 0.3 mM calcium, and in duodenum and proximal jejunum when filled with 10 mM luminal calcium. Secretory rates were in the following order: duodenum, jejunum, proximal jejunum, cecum, ileum, and proximal colon. Absorption of 0.3 mM calcium was decreased in all but the cecum and colon during hypercalcemia, and in duodenum, proximal jejunum, and colon during thyroparathyroidectomy-induced hypocalcemia. In contrast, calcium secretion was directly related to plasma calcium concentration and the length of the intestine. Functional resection of any part met with a compensatory increase in calcium absorption by the remaining segments, with the exception of the resection of the distal ileum with the large bowel. In conclusion, proximal small intestine exhibited the highest rate of absorption and secretion, but functional resection of this or any part did not affect the overall calcium absorption if luminal calcium was 10 mM. Moreover, enhanced secretion and reduced absorption during hypercalcemia were beneficial with respect to plasma calcium regulation.Key words: calcium, hypercalcemia, hypocalcemia, intestinal absorption, intestinal secretion.

scholarly journals Eukaryotic Release Factor 1 Phosphorylation by CK2 Protein Kinase Is Dynamic but Has Little Effect on the Efficiency of Translation Termination in Saccharomyces cerevisiae

2006 ◽  
Vol 5 (8) ◽  
pp. 1378-1387 ◽  
Author(s):  
Adam K. Kallmeyer ◽  
Kim M. Keeling ◽  
David M. Bedwell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Synthesis ◽  
Protein Kinase ◽  
Stop Codon ◽  
Translation Termination ◽  
Release Factor ◽  
Codon Recognition ◽  
Number Of Factors ◽  
Stop Codon Recognition

ABSTRACT Protein synthesis requires a large commitment of cellular resources and is highly regulated. Previous studies have shown that a number of factors that mediate the initiation and elongation steps of translation are regulated by phosphorylation. In this report, we show that a factor involved in the termination step of protein synthesis is also subject to phosphorylation. Our results indicate that eukaryotic release factor 1 (eRF1) is phosphorylated in vivo at serine 421 and serine 432 by the CK2 protein kinase (previously casein kinase II) in the budding yeast Saccharomyces cerevisiae. Phosphorylation of eRF1 has little effect on the efficiency of stop codon recognition or nonsense-mediated mRNA decay. Also, phosphorylation is not required for eRF1 binding to the other translation termination factor, eRF3. In addition, we provide evidence that the putative phosphatase Sal6p does not dephosphorylate eRF1 and that the state of eRF1 phosphorylation does not influence the allosuppressor phenotype associated with a sal6Δ mutation. Finally, we show that phosphorylation of eRF1 is a dynamic process that is dependent upon carbon source availability. Since many other proteins involved in protein synthesis have a CK2 protein kinase motif near their extreme C termini, we propose that this represents a common regulatory mechanism that is shared by factors involved in all three stages of protein synthesis.

The Influence of Pregnancy and Lactation on the Morphology and Absorptive Capacity of the Rat Small Intestine

1970 ◽  
Vol 38 (3) ◽  
pp. 287-295 ◽  
Author(s):  
I. L. Craft
Keyword(s):  
Small Intestine ◽  
Surface Area ◽  
Absorptive Capacity ◽  
Dry Weight ◽  
Total Weight ◽  
Rat Small Intestine ◽  
Pregnancy And Lactation ◽  
In Pregnancy

1. A study of the length, total weight and weight per cm of the small intestine of virgin, pregnant and lactating rats has provided evidence for an increase in intestinal surface area in pregnancy and lactation. 2. Because of such alterations in morphology of the gut the absorption,in vivo, of the substrates studied, glucose and glycine, has been expressed in terms of amount transferred per loop and also per g dry weight of intestine. 3. Using these parameters the results show that pregnancy does not alter the ability of the upper jejunum to absorb glucose and glycine. In lactation there is a significant decrease in the transfer of these substances when expressed per g dry weight of intestine, but not in absolute terms.

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