Microtest for the Determination of the Amylolytic Activity of Saliva Alpha-Amylase

Abstract

It is known that the concentration of alpha-amylase in saliva can determine its catalytic activity, the decrease of which occurs during various pathological processes in the oral cavity. The overwhelming number of methods for determining the catalytic activity of enzymes involve the use of a large volume of reagents and samples, which makes it difficult to study saliva in large groups. The purpose of the study is to evaluate the possibility of using the microvariation of the reaction to determine the activity of saliva alpha-amylase, as well as to analyze the dependence of the enzyme activity on its concentration. Materials and methods. Saliva was obtained from 15 people with intact periodontal disease and the dentition, without somatic pathology. For in vitro studies, alpha-amylase solutions were prepared with an enzyme concentration of 10; five; 2.5; one; 0.5 and 0.25 mg / ml ex tempore. To save samples and reagents, the volume of the reaction participants was proportionally reduced. The further analysis procedure was carried out according to the instructions of the manufacturer of the «AMYLASE-VITAL» reagent kit to determine the activity of alpha-amylase. Statistical analysis of the results was performed using the Student’s t-test in the program Statistica 7.0. Results. The comparability of the results of determining the activity of alpha-amylase using the classical and microplate variants of the reaction is shown. With an increase in alpha-amylase concentration from 0 to 2.5 mg / ml, a directly proportional increase in enzyme activity is observed. In the case of an increase in the concentration of alpha-amylase above 2.5 mg / ml, a decrease in its activity is shown, which may be due to the precipitation of a part of the enzyme. The activity of the enzyme in saliva of practically healthy individuals using the microvariation of the reaction was 528.6 ± 2.4 U / l. In conclusion the use of a microvariant of the reaction for determining the activity of alpha-amylase may be justified for a large number of subjects. A linear dependence of the enzyme activity on its concentration in the range of 0-2.5 mg / ml is shown.