井澤他：爪コルチゾールの定量手法 ― 245 ― 爪に含まれるコルチゾールの定量手法の検討 ――粉砕粒度と抽出時間の検討―― 1 井澤　修平 （労働安全衛生総合研究所） 吉田　怜楠 （長岡技術科学大学工学研究科） 大平　雅子 （滋賀大学教育学部） 山口　歩・野村　収作 （長岡技術科学大学工学研究科） Quantitative Measurements of Fingernail Cortisol: Effects of Ground-fingernail Grain Size and Extraction Time Shuhei IZAWA (National Institute of Occupational Safety and Health, Japan) Reina Y OSHIDA (Faculty of Engineering, Nagaoka University of Technology) Masako HASEGAWA-OHIRA (Faculty of Education, Shiga University) Ayumi Y AMAGUCHI, Shusaku NOMURA (Faculty of Engineering, Nagaoka University of Technology) Although cortisol levels in fingernails may reflect the hormone’ s long-term cumulative production, a standard measuring procedure has not yet been established. In this study, we investigated the effects of ground-fingernail grain size and cortisol extraction time on the measurement of fingernail cortisol. Fourteen healthy males provided fingernail samples, which were ground for 1, 4, or 16 minutes (coarse-, medium-, or fine-grading conditions, respectively). Subsequently, cortisol was extracted in pure methanol for 1, 6, 24, or 48 hours (four extraction time conditions). The clear supernatant was filtered and dried, and extracted cortisol was measured using an enzyme-linked immunosorbent assay. ANOVA results indicated that finer grading and longer extraction time was associated with higher cortisol levels. Furthermore, an interaction between grading and extraction-time conditions was observed: cortisol levels between medium- and fine-grading conditions were comparable in 48-hour extraction. This study clearly demonstrated that the grain-size of ground fingernails and extraction time could affect the amount of extracted cortisol obtained from fingernails and should therefore be considered during fingernail cortisol assay. Key words: fingernail, cortisol, stress, enzyme-linked immunosorbent assay 生理心理学と精神生理学　34 （3）　245‒249, 2016 2016.5.9 受稿，2016.9.22 受理，2018.3.23 J-STAGE 早期公開，doi: 10.5674/jjppp.1615tn 連絡者及び連絡先：〒940‒2188 住所　新潟県長岡市上富岡町1603‒1 長岡技術科学大学大学院工学研究科　野村収作 E-mail: nomura@kjs.nagaokaut.ac.jp 1 本研究は，JSPS 科研費15K13169 （爪試料を利用した慢性的・蓄積的なコルチゾール分泌の評価法の確立）の助成を受けた。 テクニカルノート