Desensitization of TRPV1 Involved in the Antipruritic Effect of Osthole on Histamine-Induced Scratching Behavior in Mice

Figure 6

Osthole desensitized capsaicin-induced calcium influx. (a, b) Representative traces showed the effect of pretreatment with 10 μM and 30 μM osthole on capsaicin-induced calcium influx. (c) Representative traces showed the effect of pretreatment capsaicin on secondary capsaicin-induced calcium influx. (d) The mean amplitudes of capsaicin-induced calcium influx were significantly different with pretreatment of osthole or capsaicin. Fluorescence intensity of capsaicin treated alone is 0.72 ± 0.04 and treated secondly is 0.26 ± 0.06 (cells = 161 (positive)/1785 (total), n = 3 animals). Fluorescence intensities of capsaicin after treatment with 10 μM and 30 μM osthole are 0.69 ± 0.05 (cells = 106 (positive)/1650 (total), n = 3 animals) and 0.57 ± 0.03 (cells = 102 (positive)/1360 (total), n = 3 animals). Cap, capsaicin (, , one-way ANOVA followed by Dunnett’s test versus capsaicin treated alone).

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