scholarly journals Inorganic Phosphate Transport and Phosphate Homeostasis in Plant Cells

Root Research ◽  
1993 ◽  
Vol 2 (3) ◽  
pp. 89-92
Author(s):  
Tetsuro MIMURA
Keyword(s):  
Inorganic Phosphate ◽  
Plant Cells ◽  
Phosphate Transport ◽  
Phosphate Homeostasis

Physiological control of phosphate uptake and phosphate homeostasis in plant cells

2001 ◽  
Vol 28 (7) ◽  
pp. 655 ◽  
Author(s):  
Tetsuro Mimura
Keyword(s):  
Plasma Membrane ◽  
Driving Force ◽  
Inorganic Phosphate ◽  
Phosphate Uptake ◽  
Plant Cells ◽  
Phosphate Homeostasis ◽  
Physiological Control ◽  
Physiological Level ◽  
Pi Transport ◽  
Cytoplasmic Acidification

Inorganic phosphate (Pi) uptake systems across the plasma membrane of plant cells have been extensively investigated. Physiological studies have established that Pi is transported into plant cells via co-transport with H+ , and in some plants with Na + , using the driving force provided by the electrogenic H + pump in the plasma membrane. Molecular studies have identified many genes for Pi transporters and are providing insights into the mechanisms of genetic control of Pi transport. There still remain, however, questions as to how Pi uptake systems are regulated at the physiological level. We have found that Pi uptake induces cytoplasmic acidification, and, conversely, that inducing cytoplasmic acidification causes the cytoplasmic Pi concentration to decrease. Both of these responses affect the operation of the H + -pump. These phenomena are discussed in relation to a possible mechanism for the physiological control of Pi uptake by plant cells.

scholarly journals The Complexities of Organ Crosstalk in Phosphate Homeostasis: Time to Put Phosphate Sensing Back in the Limelight

2021 ◽  
Vol 22 (11) ◽  
pp. 5701
Author(s):  
Lucile Figueres ◽  
Sarah Beck-Cormier ◽  
Laurent Beck ◽  
Joanne Marks
Keyword(s):  
Molecular Mechanisms ◽  
Dominant Role ◽  
Fibroblast Growth Factor 23 ◽  
Hormone Secretion ◽  
Phosphate Transport ◽  
Phosphate Homeostasis ◽  
Cellular Mechanisms ◽  
Exact Function ◽  
Phosphate Sensing ◽  
Significant Research

Phosphate homeostasis is essential for health and is achieved via interaction between the bone, kidney, small intestine, and parathyroid glands and via intricate processes involving phosphate transporters, phosphate sensors, and circulating hormones. Numerous genetic and acquired disorders are associated with disruption in these processes and can lead to significant morbidity and mortality. The role of the kidney in phosphate homeostasis is well known, although it is recognized that the cellular mechanisms in murine models and humans are different. Intestinal phosphate transport also appears to differ in humans and rodents, with recent studies demonstrating a dominant role for the paracellular pathway. The existence of phosphate sensing has been acknowledged for decades; however, the underlying molecular mechanisms are poorly understood. At least three phosphate sensors have emerged. PiT2 and FGFR1c both act as phosphate sensors controlling Fibroblast Growth Factor 23 secretion in bone, whereas the calcium-sensing receptor controls parathyroid hormone secretion in response to extracellular phosphate. All three of the proposed sensors are expressed in the kidney and intestine but their exact function in these organs is unknown. Understanding organ interactions and the mechanisms involved in phosphate sensing requires significant research to develop novel approaches for the treatment of phosphate homeostasis disorders.

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.

HOMEOSTATIC ADJUSTMENT IN THE RENAL TUBULAR TRANSPORT OF INORGANIC PHOSPHATE IN THE DOG

1955 ◽  
Vol 33 (1) ◽  
pp. 638-650 ◽  
Author(s):  
James G. Foulks
Keyword(s):  
Inorganic Phosphate ◽  
Renal Tubule ◽  
Phosphate Transport ◽  
Sodium Sulphate ◽  
Tubular Transport ◽  
Renal Tubular Transport ◽  
Transport Of Inorganic Phosphate ◽  
Renal Tubular ◽  
Filtered Load

By means of the infusion of small amounts of sodium sulphate it has been possible to elevate the filtered load of inorganic phosphate to the renal tubule in fasted dogs without the administration of exogenous phosphate. Under these circumstances, the reabsorption of phosphate remains virtually complete, even when filtered loads are reached which result in a substantial phosphaturia when phosphate has been administered. By comparing phosphate reabsorption and excretion in fasted animals, and in animals at various intervals after feeding, the existence of homeostatic adjustments in the renal tubular transport of inorganic phosphate has been demonstrated. The available evidence suggests that the intracellular disposition of phosphate itself may be an important factor in determining the rate of renal tubular phosphate transport at filtered loads in the physiological range. The limitations of the determination of the phosphate "Tm" as a device for studying homeostatic processes have been discussed.

Does Availability of Inorganic Phosphate Regulate Cellular Oxidative Metabolism?

Physiology ◽  
1986 ◽  
Vol 1 (3) ◽  
pp. 100-103 ◽  
Author(s):  
PC Brazy ◽  
LJ Mandel
Keyword(s):  
Solute Transport ◽  
Oxidative Metabolism ◽  
Inorganic Phosphate ◽  
Phosphate Transport ◽  
Renal Tubules ◽  
Metabolic Processes

Cells require inorganic phosphate for formation of ATP and a variety of other metabolic and transport functions. Studies of renal tubules indicate that availability of phosphate does regulate rates of oxidative metabolism and solute transport, that intracellular metabolic processes compete for inorganic phosphate, and that transepithelial phosphate transport provides inorganic phosphate for use within the cell.

HOMEOSTATIC ADJUSTMENT IN THE RENAL TUBULAR TRANSPORT OF INORGANIC PHOSPHATE IN THE DOG

1955 ◽  
Vol 33 (4) ◽  
pp. 638-650 ◽  
Author(s):  
James G. Foulks
Keyword(s):  
Inorganic Phosphate ◽  
Renal Tubule ◽  
Phosphate Transport ◽  
Sodium Sulphate ◽  
Tubular Transport ◽  
Renal Tubular Transport ◽  
Transport Of Inorganic Phosphate ◽  
Renal Tubular ◽  
Filtered Load

By means of the infusion of small amounts of sodium sulphate it has been possible to elevate the filtered load of inorganic phosphate to the renal tubule in fasted dogs without the administration of exogenous phosphate. Under these circumstances, the reabsorption of phosphate remains virtually complete, even when filtered loads are reached which result in a substantial phosphaturia when phosphate has been administered. By comparing phosphate reabsorption and excretion in fasted animals, and in animals at various intervals after feeding, the existence of homeostatic adjustments in the renal tubular transport of inorganic phosphate has been demonstrated. The available evidence suggests that the intracellular disposition of phosphate itself may be an important factor in determining the rate of renal tubular phosphate transport at filtered loads in the physiological range. The limitations of the determination of the phosphate "Tm" as a device for studying homeostatic processes have been discussed.

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