ランダルセリット法による痛覚閾値測定はプローブ直径に依存して異なる組織の機械逃避閾値を反映する。 Randall-Selitto device measures the mechanical withdrawal thresholds of different tissues in rats depending on its probe diameter

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Author(s)

    • 那須 輝顕 Nasu Teruaki
    • 名古屋大学・環境医学研究所・神経系2・ストレス受容応答研究部門 Div.Stress Recognition and Response Dept.Neuroscience, Res. Inst. Environ. Med., Nagoya Univ, Nagoya Japan
    • 寺澤 悦司 Terazawa Etsuji
    • 名古屋大学・環境医学研究所・神経系2・ストレス受容応答研究部門 Div.Stress Recognition and Response Dept.Neuroscience, Res. Inst. Environ. Med., Nagoya Univ, Nagoya Japan
    • 佐藤 純 Sato Jun
    • 名古屋大学・環境医学研究所・神経系2・ストレス受容応答研究部門 Div.Stress Recognition and Response Dept.Neuroscience, Res. Inst. Environ. Med., Nagoya Univ, Nagoya Japan
    • 水村 和枝 Mizumura Kazue
    • 名古屋大学・環境医学研究所・神経系2・ストレス受容応答研究部門 Div.Stress Recognition and Response Dept.Neuroscience, Res. Inst. Environ. Med., Nagoya Univ, Nagoya Japan

Abstract

There are many studies measuring the mechanical withdrawal threshold (MWT) in animals with Randall-Selitto (RS) apparatus, however, it is not clear which tissue's threshold RS device measures. In our previous human experiment with surface anesthesia, we showed that a probe larger than 2 mm measured the pain threshold of deep tissues (possibly muscles) while a smaller probe measured the skin pain threshold. To know the influence of probe diameter on the depth of tissues MWT of which the RS apparatus measures, we examined two probes of different diameters (normal probe with tip diameter 1.3 mm originally attached to the RS device and modified probe with tip diameter 2.6 mm made by our lab), and effect of surface anesthesia (EMLA cream containing 2.5% lidocaine and 2.5% prirocaine, for 30 min) on MWT measures with these probes. For comparison, MWT was also measured with von Frey hair (VFH, 0.5 mm tip diameter). SD rats (n=27) were used in this study. Surface anesthesia increased the MWT measured with von Frey hairs and that measured with the normal probe-equipped RS device. In contrast, MWT measured with the larger probe-equipped one was not influenced by surface anesthesia. These data demonstrated that the WMT measured with VFH and normal probe-equipped RS device reflects the cutaneous pain threshold while that measured with larger probe-equipped RS apparatus reflects the pain threshold in deep tissues. <b>[J Physiol Sci. 2007;57 Suppl:S112]</b>

There are many studies measuring the mechanical withdrawal threshold (MWT) in animals with Randall-Selitto (RS) apparatus, however, it is not clear which tissue's threshold RS device measures. In our previous human experiment with surface anesthesia, we showed that a probe larger than 2 mm measured the pain threshold of deep tissues (possibly muscles) while a smaller probe measured the skin pain threshold. To know the influence of probe diameter on the depth of tissues MWT of which the RS apparatus measures, we examined two probes of different diameters (normal probe with tip diameter 1.3 mm originally attached to the RS device and modified probe with tip diameter 2.6 mm made by our lab), and effect of surface anesthesia (EMLA cream containing 2.5% lidocaine and 2.5% prirocaine, for 30 min) on MWT measures with these probes. For comparison, MWT was also measured with von Frey hair (VFH, 0.5 mm tip diameter). SD rats (n=27) were used in this study. Surface anesthesia increased the MWT measured with von Frey hairs and that measured with the normal probe-equipped RS device. In contrast, MWT measured with the larger probe-equipped one was not influenced by surface anesthesia. These data demonstrated that the WMT measured with VFH and normal probe-equipped RS device reflects the cutaneous pain threshold while that measured with larger probe-equipped RS apparatus reflects the pain threshold in deep tissues. <b>[J Physiol Sci. 2007;57 Suppl:S112]</b>

Journal

  • Proceedings of Annual Meeting of the Physiological Society of Japan

    Proceedings of Annual Meeting of the Physiological Society of Japan 2007(0), 112-112, 2007

    PHYSIOLOGICAL SOCIETY OF JAPAN

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