Inorganic Phosphate Absorption in Small Intestine

2011 ◽  
Author(s):  
Giustina Danisi ◽  
Heini Murer
Keyword(s):  
Small Intestine ◽  
Inorganic Phosphate ◽  
Phosphate Absorption

Absorption of Inorganic Phosphate in the Human Small Intestine

1979 ◽  
Vol 56 (5) ◽  
pp. 407-412 ◽  
Author(s):  
J. Walton ◽  
T. K. Gray
Keyword(s):  
Small Intestine ◽  
Inorganic Phosphate ◽  
Water Movement ◽  
Human Subjects ◽  
Sodium Concentration ◽  
Phosphate Concentration ◽  
Phosphate Absorption ◽  
Human Small Intestine ◽  
Intestinal Phosphate Absorption

1. Intestinal phosphate absorption in human subjects was studied by the technique of triple lumen intestinal perfusion in vivo. 2. Ileal phosphate absorption increased as the intraluminal phosphate concentration was increased. 3. Ileal rates of phosphate absorption were lower at any given intraluminal phosphate concentration than previously described jejunal rates. Acidification of the ileal lumen did not increase phosphate absorption. 4. Phosphate absorption was shown in the jejunum to be dependent on the intraluminal sodium concentration. 5. Phosphate absorption in the human small intestine consists of at least two components, one directly proportional to water movement and the second apparently independent of water movement.

Sodium, potassium, and intestinal transport of glucose, l-tyrosine, phosphate, and calcium

1963 ◽  
Vol 205 (1) ◽  
pp. 107-111 ◽  
Author(s):  
Harold E. Harrison ◽  
Helen C. Harrison
Keyword(s):  
Small Intestine ◽  
Calcium Transport ◽  
Inorganic Phosphate ◽  
Choline Chloride ◽  
Sodium Concentration ◽  
Phosphate Transport ◽  
Metabolic Energy ◽  
Transport Systems ◽  
Bicarbonate Buffer ◽  
Distal Small Intestine

Everted loops of rat small intestine were incubated in media varying in their concentrations of sodium and potassium. Reduction of sodium concentration was effected by substitution of choline chloride in equimolar amounts for sodium chloride in the saline-bicarbonate buffer. Concentrative transport of glucose, l-tyrosine, inorganic phosphate, and calcium was measured by determination of the final ratio of the concentrations of the solute in serosal and mucosal fluids, and the increment of the solute in serosal fluid during incubation. Ca45 was used as an indicator of calcium distribution. The glucose, l-tyrosine, and inorganic phosphate transport systems require sodium, and at a submaximal concentration of sodium an increased concentration of potassium is inhibitory. The calcium transport system does not require sodium and in loops from the distal small intestine calcium transport is enhanced by reduction of sodium concentration in the medium. It is postulated that there is a common sodium-requiring system which is necessary for the linkage of metabolic energy to glucose, amino acid, and inorganic phosphate transport.

Phosphate homeostasis and the renal-gastrointestinal axis

2010 ◽  
Vol 299 (2) ◽  
pp. F285-F296 ◽  
Author(s):  
Joanne Marks ◽  
Edward S. Debnam ◽  
Robert J. Unwin
Keyword(s):  
Small Intestine ◽  
Phosphate Transport ◽  
Phosphate Absorption ◽  
Renal Phosphate Reabsorption ◽  
Sodium Dependent ◽  
Dietary Phosphate ◽  
Intestinal Phosphate Absorption ◽  
End Stage ◽  
And Control ◽  
Renal Phosphate Excretion

Transport of phosphate across intestinal and renal epithelia is essential for normal phosphate balance, yet we know less about the mechanisms and regulation of intestinal phosphate absorption than we do about phosphate handling by the kidney. Recent studies have provided strong evidence that the sodium-phosphate cotransporter NaPi-IIb is responsible for sodium-dependent phosphate absorption by the small intestine, and it might be that this protein can link changes in dietary phosphate to altered renal phosphate excretion to maintain phosphate balance. Evidence is also emerging that specific regions of the small intestine adapt differently to acute or chronic changes in dietary phosphate load and that phosphatonins inhibit both renal and intestinal phosphate transport. This review summarizes our current understanding of the mechanisms and control of intestinal phosphate absorption and how it may be related to renal phosphate reabsorption; it also considers the ways in which the gut could be targeted to prevent, or limit, hyperphosphatemia in chronic and end-stage renal failure.

scholarly journals Binding of magnesium and calcium in the contents of the small intestine of the calf

1966 ◽  
Vol 20 (4) ◽  
pp. 703-718 ◽  
Author(s):  
R. H. Smith ◽  
A. B. McAllan
Keyword(s):  
Small Intestine ◽  
Inorganic Phosphate ◽  
Practical Importance ◽  
The Other ◽  
Ammonium Ion ◽  
Phosphate Binding ◽  
Binding Material ◽  
Single Substance

1. In ileal contents from differently fed ruminating calves, examined under conditions approximating to those obtaining in vivo, 34–74% of the magnesium and 63–93% of the calcium were non-ultrafilterable. The binding was shown to be due to at least two processes, one depending on the presence of phosphate, the other not. 2. Considerable non-phosphate binding occurred in samples adjusted in vitro to pH 5.5 and above. The binding material was probably not a single substance but the bound forms of both Mg and Ca were, at least partly, in equilibrium with the soluble forms, and some competition between the two metals occurred. Thus in any one sample the extent of binding for either metal was influenced by the concentration of both. With normal concentrations it was estimated that, in the ileum, about one-third of the Mg and half of the Ca was bound in this way, irrespective of whether pasture or one of a variety of stall diets was given. 3. Samples adjusted to about pH 6.5 and above (in vivo ileum pH was about 7.4–7.9) showed further precipitation of Ca and Mg to an extent which partly depended on the concentration of inorganic phosphate. Ca precipitation appeared to be mainly controlled by the concentration of Ca and inorganic phosphate but for Mg the precipitation depended also on the presence of factors other than Mg and inorganic phosphate. One such factor found to be present was the ammonium ion, but its practical importance is uncertain. 4. Ileal contents from milk-fed calves showed considerable non-phosphate binding of Ca but not of Mg.

THE EFFECT OF THYROXINE ON THE MOVEMENT OF CALCIUM AND INORGANIC PHOSPHATE THROUGH THE SMALL INTESTINE OF THE RAT

1967 ◽  
Vol 37 (2) ◽  
pp. 111-117 ◽  
Author(s):  
H. M. NOBLE ◽  
A. J. MATTY
Keyword(s):  
Body Weight ◽  
Small Intestine ◽  
Basement Membrane ◽  
Active Transport ◽  
Inorganic Phosphate ◽  
Young Female ◽  
Passive Movement ◽  
Single Site ◽  
Female Rats ◽  
Daily Injection

SUMMARY Young female rats were given a daily injection of 1 mg. thyroxine/kg. body weight for 7 days. They were killed on the eighth day and the small intestine used for a study of the movement of radioactive calcium and inorganic phosphate. The everted sac technique was used. The results indicate that the passive movement of phosphate was depressed. Both the passive and active transport of calcium were also depressed. It is suggested that the transport of calcium and the transport of phosphate, whether active or passive, are related and that thyroxine affects a single site located perhaps at the basement membrane of the mucosa.

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