Determination of lactate and lactic dehydrogenase by biamperometric monitoring of hexacyanoferrate(II) in a flowing stream

1979 ◽  
Vol 295 (2-3) ◽  
pp. 157-160 ◽  
Author(s):  
Abdulrahman S. Attiyat ◽  
Gary D. Christian
Keyword(s):  
Lactic Dehydrogenase ◽  
Flowing Stream

Optimal Conditions for the Enzymatic Determination of L-Lactic Acid

1962 ◽  
Vol 8 (1) ◽  
pp. 1-10 ◽  
Author(s):  
G F Olson
Keyword(s):  
Lactic Acid ◽  
Heart Muscle ◽  
Lactic Dehydrogenase ◽  
Test System ◽  
Optimal Conditions ◽  
Enzymatic Method ◽  
Chemical Methods ◽  
Enzymatic Determination ◽  
Enzymatic Procedure

Abstract A simple enzymatic method for the determination of lactic acid with muscle lactic dehydrogenase is described. L(+) Lactate in amounts from 0.04 µM to 0.4 µM can be directly measured by following the formation of reduced diphosphopyridine nucleotide at 340 mµ. The effect of varying the concentrations of reactants in the test system was studied, and the optimal concentrations for stoichiometric conversion of lactate to pyruvate were determined. When lactic acid concentrations in plasma, liver, and heart muscle were determined by both enzymatic and chemical methods, identical results were obtained. The advantages of the present enzymatic procedure over chemical methods are discussed.

Application of the PEDD flow detector for analysis of natural dissolved organic substances in coloured water

2013 ◽  
Vol 68 (1) ◽  
pp. 29-35 ◽  
Author(s):  
B. Libecki ◽  
S. Kalinowski
Keyword(s):  
Flow Analysis ◽  
High Sensitivity ◽  
Flow Cell ◽  
Sequential Injection Analysis ◽  
Organic Substances ◽  
Water Parameters ◽  
Light Emitting ◽  
Flowing Stream ◽  
Detector Diode

The automated techniques of measurement of water parameters are developed based on flow analysis (flow injection analysis, sequential injection analysis). PEDD detectors (paired emitter–detector diode), built with the use of two paired light-emitting diodes (LEDs) – emission and detection, can serve that purpose. The aim of the studies was to optimize the system for determination of the dissolved organic substances in coloured water with the use of PEDDs in the flowing-stream measurement system. The investigations were conducted for a number of concentrations of the humic, fulvic and tannic acids, which were measured as the dissolved organic carbon (DOC). Three arrangements of diodes (PEDD) with a selected emission spectrum and absorption characteristics were used. A two-beam flow cell was designed for the measurements. The signal from the detection diode was recorded and converted into absorbance through software written for that purpose. The results obtained showed a high sensitivity in relation to the concentration as well as the selectivity in the type of substances studied. A miniature and cheap photometric flow analysis set was proposed, adapted to work with one or several light wavelengths and steered by a microprocessor unit.

Automatic Determination of Lactic Acid in Blood

1969 ◽  
Vol 15 (10) ◽  
pp. 940-948 ◽  
Author(s):  
T P Hadjiioannou ◽  
P A Siskos ◽  
C G Valkana
Keyword(s):  
Lactic Acid ◽  
Reaction Rate ◽  
Lactic Dehydrogenase ◽  
Lactic Acid Concentration ◽  
Automatic Determination ◽  
Fixed Amount ◽  
Rate Method ◽  
Relative Errors ◽  
Time Required

Abstract An automatic reaction rate method is described for the determination of lactic acid in blood. The L(+)-lactic acid is selectively oxidized in the presence of lactic dehydrogenase and diphosphopyridine nucleotide to form an absorbing species. The time required for the formation of a fixed amount of DANH is measured automatically and related directly to the lactic acid concentration. The method is sensitive, more rapid than purely chemical procedures, and relative errors are only about 1-3% for the range 6-200 µg of lactic acid. The coefficient of variation for the determination of lactic acid in 0.2 ml of blood is 3%. Measurement times vary from a few seconds to about 2 min.

Energy metabolism in kidney of heat-acclimated hamsters

1975 ◽  
Vol 229 (5) ◽  
pp. 1234-1236 ◽  
Author(s):  
I Inbar ◽  
R Chayoth ◽  
Y Cassuto
Keyword(s):  
Energy Metabolism ◽  
Glycogen Content ◽  
Heat Acclimation ◽  
Lactic Dehydrogenase ◽  
Isolated Kidney ◽  
Kidney Mitochondria ◽  
Cytochromes C ◽  
Ratio Determination ◽  
Glucose 6 Phosphate Dehydrogenase

Biochemical pathways which are involved in energy metabolism were examined in the kidney of heat-acclimated hamsters. It was found that heat acclimation caused 47% reduction in glucose-6-phosphatase (G1c-6-Pase) activity and 40% lower rate of gluconeogenesis. No changes were found in the activity of hexokinase, glucose-6-phosphate dehydrogenase, pyruvate kinase, lactic dehydrogenase, or in kidney glycogen content. Isolated kidney mitochondria of heat-acclimated hamsters utilized 15% less oxygen than that of controls, but no differences were found in the P/O ratio. Determination of the content of some cytochromes showed a significant reduction in cytochromes c + c1, but no difference was found in the content of cytochromes a, a3, and b. These results suggest that the kidney plays a role in the reduction of energy metabolism during the process of heat acclimation.

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