Determination of nucleoside triphosphatase activities from measurement of true inorganic phosphate in the presence of labile phosphate compounds

Abstract We describe an enzymatic method for determining inorganic phosphate in serum and urine, with use of the "CentrifiChem." The sample is mixed with a combined enzyme—substrate system consisting of the enzymes phosphorylase a, phosphoglucomutase, and glucose-6-phosphate dehydrogenase, the coenzyme NADP, the substrate glycogen, and adenosine 5'-monophosphate as the activator for phosphorylase. The increase in absorbance at 340 nm as NADPH is formed is linearly proportional to the concentration of inorganic phosphate to 15 mg P/dl. This method circumvents deproteinization and requires only 10 µl of sample. Results obtained with the automated enzymatic method show good correlation with manual and automated molybdenum blue methods.

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Improved method for measurement of inorganic phosphate in serum with a centrifugal analyzer.

Clinical Chemistry ◽

10.1093/clinchem/22.2.257 ◽

1976 ◽

Vol 22 (2) ◽

pp. 257-260 ◽

Cited By ~ 2

Author(s):

P W Wentz ◽

J Savory ◽

R E Cross

Keyword(s):

Plasma Cell ◽

Data Reduction ◽

Continuous Flow ◽

Inorganic Phosphate ◽

High Speed ◽

Improved Method ◽

Plasma Cell Dyscrasias

Abstract A direct mehtod [Clin. Chim. Acta 46, 113 (1973)] for determination of inorganic phosphate in serum was adapted for use with a centrifugal analyzer. Contamination is minimized and analysis rate maximized by doing the reaction in the reagent wells of the transfer disc and by utilizing the high-speed spectrophotometric and data-reduction capabilities of the centrifugal analyzer. Hemolysis, icterus, and moderate lipemia cause no interference. Grossly lipemic sera and sera from patients with plasma cell dyscrasias can be analyzed by incorporating appropriate blanking and dilution techniques. The method exhibits excellent sensitivity and precision and results correlate well with those from a continuous-flow procedure.

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

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y55-079 ◽

1955 ◽

Vol 33 (1) ◽

pp. 638-650 ◽

Cited By ~ 2

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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A simple automated method for determination of low concentrations of inorganic phosphate

Analytical Biochemistry ◽

10.1016/0003-2697(72)90060-7 ◽

1972 ◽

Vol 50 (2) ◽

pp. 503-508 ◽

Cited By ~ 1

Author(s):

E. Ehrlich ◽

R. Coelho ◽

F. Guillain

Keyword(s):

Inorganic Phosphate ◽

Automated Method ◽

Low Concentrations

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

Canadian Journal of Biochemistry and Physiology ◽

10.1139/o55-079 ◽

1955 ◽

Vol 33 (4) ◽

pp. 638-650 ◽

Cited By ~ 6

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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Some Methodological Modifications of the Technicon "SMA 12/60 AutoAnalyzer" System

Clinical Chemistry ◽

10.1093/clinchem/18.7.630 ◽

1972 ◽

Vol 18 (7) ◽

pp. 630-642 ◽

Cited By ~ 8

Author(s):

Tevfik K Bigat ◽

Abraham Saifer

Keyword(s):

Alkaline Phosphatase ◽

Glucose Oxidase ◽

Aspartate Aminotransferase ◽

Inorganic Phosphate ◽

New Method ◽

Green Method ◽

Bromcresol Green ◽

Made In

Abstract Methodological modifications have been made in our "SMA 12/60 AutoAnalyzer" system, to improve the reproducibility and accuracy of six commonly performed procedures. These include glucose with the glucose oxidase method, albumin with the bromcresol green method, and alkaline phosphatase with the sodium thymolphthalein monophosphate method. We have also modified the composition of the reagents used in the determination of protein, inorganic phosphate, and aspartate aminotransferase. A general approach that is useful for adapting a new method to a multichannel AutoAnalyzer system is discussed.

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