[Device for measuring salivary alpha-amylase--application for pain assessment]

The salivary enzyme alpha-amylase is an established non-invasive marker of psychological and physiological stress. Since there are positive correlations between salivary alpha-amylase secretion and sympathetic parameter increment during stress, salivary alpha-amylase might be an indicator of sympathetic-adrenal-medullary (SAM) system and central sympathetic activity In contrast, it is well known that sympathetic neural activity is significantly involved in development and deterioration of pain symptoms as a part of pain disorders. Additionally, it has been suggested that various painful stimuli activate SAM system. Taking these data together, salivary alpha-amylase might be an indirect indicator of pain-induced central sympathetic tone. Furthermore, a hand-held device, which is able to measure the activity of salivary alpha-amylase easily and quickly, was developed recently, and we can try to evaluate the condition of pain at the outpatient clinic and the bedside. Though the actual utility of this measuring device for clinical use is unclear, it is hoped that the measuring device of salivary alpha-amylase is one of helpful methods for pain assessment in the future.