Measurement of salivary α-amylase activity by different methods and their usage in stress physiology

Measurement of Salivary α-Amylase Activity by Different Methods and Their Usage in Stress Physiology Aim:Theaim of current study was to compare three available α-amylase methods for saliva and to search for their possible usage in stress physiology. Material and Method: Starch-iodine method, substrate (CNPG3) method and dinitrosalisilic acid method were studied and their advantages and disadvantages were established. In order to test the performance of these methods, salivary samples were collected from 16 to 20 years old male elit archers (n=7) competing in Turkish indoor championship with olympic bow. Salivary samples were collected immediately following waking up at 0, 30, 45 and 60 min on three different days of the championship (ranking, elimination and team shooting). In addition, during ranking and elimination days, salivary samples were collected at 30 and 15 min before shootings, at half-time, and at the end of the shootings. Results: Starch-iodine method and CNPG3 tests were successfully established but DNS test appeared unsuitable as the samples could not be read by the standard curve formed. Sensitivity and dynamic range of the methods were suitable and 4000x and 5x dilutions were required for starch iodine method and CNPG3 method, respectively. There was a weak but statistically significant positive correlation between two tests established (For linear regression: R2=0.048; p<0.05; For quadratic regression R2=0.106; P<0.01). There were individual differences in salivary α-amylase activities both during waking up and competition periods. Conclusion: It has been determined that starch-iodine and CNPG3 methods are cheap, easily applicable, short and suitable for stress physiology studies. Starch iodine test was cheaper than the CNPG3 but the latter was more practical as it involved less stages. Key Words: Saliva, α-amylase, CNPG3, DNS, Starch-iodine, Stressphysiology