Tokai Univ. School of Med. Molecular Life Sciences

Kajiwara K.

Kajiwara, Kagemasa Dental MD Ph.D

Research Unit

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Qualitative measurement of pain by analysing the salivary alpha amylase

The purpose of the study was to develop a qualitative measurement for pain by measuring salivary alphaamylase (sAA). In this study, sAA levels were measured in order to investigate the relativity betweenfluctuation of sAA and pain on Institute of Cancer Research (ICR) mice by injection needle as a physi-cal stimulus. Mice were chosen as an object of experiment since mice and human have similarities inboth physical behaviour and biological behaviour. Here, ICR mice were divided into two groups; injectedby Nanopass 33 (TERUMO Corporation, 100 m and 200 m in inner and outer diameter) and a con-trol (without any injection). Whole saliva was collected from the oral cavity by micropipette for bothgroups. As a result, there was a significant difference in sAA levels between the two groups as the pvalue (probability value) was below than 0.01 (p < 0.01). Therefore, this is the first study showing thenon-invasive method of qualitative pain measurement for minor damage caused by physical stimulus.The results demonstrate the potential of sAA as an indirect marker for pain and suggest that the presentexperimental situation is a suitable experimental model for measuring pain.


Comparison of sAA between the stimulation group and the control group.

Please refer to the following article for further information.

Tsuchiya, K. et al, Precision Engineering 38 (2014) 257–260.