Change in the Secretion of Salivary Cortisol, Immunoglobulin A, and Alpha-amylase while Asleep

Abstract

(OBJECTIVE) The change in the secretion of stress-related bio-chemical substances, which are cortisol, immunoglobulin A (sIgA), and alpha-amylase, while asleep was regarded. As for the sample collection, we developed and proposed a saliva collection technique as a non-invasive and non-disturbing manner of sample collection while asleep, whereas the blood collection should impose greater psycho-physiological stresses to subjects. (METHOD) Subjects, 10 male university students, were instructed to take a 6-hour of sleep from 0:00 of the midnight to 6:00 in the morning at the environmental controlled room, where electrocardiogram (ECG) and blood pressure (BP) were measured, and saliva collection was made continuously in the time series. (RESULT) Salivary sIgA and alpha-amylase concentration obtained by saliva samples depicted a similar profile in the time series, i. e. gradually increase while subjects were asleep, and dropped to the initial level right after awakening. Meanwhile cortisol remained the same level while asleep and got started to increase right after awakening and reached at a peak around 40 minutes later. (CONCLUSION) We developed and proposed our own saliva collection technique for the purpose of non-invasive sample collection while asleep. As a developing result, the distinctive difference in the secretion of stress-related substances was illustrated;which might be derived from the difference in the stress-reaction pathways in our body.