engleski

Direct Potentiometric Determination of Ptyalin in Saliva

The application of platinum redox electrode for potentiometric determination of salivary α-amylase (ptyalin) is described. Ptyalin, an enzyme present in human saliva, catalyses the hydrolysis of starch. The nonhydrolysed starch, which amount is inversely proportional to the ptyalin concentration, forms a complex with triiodide reducing accordingly initial triiodide concentration. The change of triiodide ion concentration causes the change of the triiodide/iodide redox-couple ratio, which results with the changes of the electrode potential of a redox-sensor. The changes are directly correlated with ptyalin concentration. The experimental data were compared with an appropriate theoretical model in which the sensor and analyte properties were optimized with Solver using the least-squares criterion to fit a theoretical curve to the experimental data set. The influence of physical activity on the ptyalin level in saliva was also investigated. It was found that ptyalin concentration in the rowers saliva strongly increases after their exposing to stronger physical activity (training), even by 2, 6 to 7 times in comparison with ptyaline level before training. The influence of alcohol consumption to the ptyalin level in saliva has opposite effect, i.e. after alcohol consumption the ptyalin activity/concentration dramatically desreases by 9, 5 - 24, 9 times compared to its activity before alcohol consumption.

ptyalin; saliva; direct potentiometry; stress

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