Figure 4

Cd-influx into the cells through TRPA1. (A) Actual recordings of the changes in the fluorescent ratio induced by Cd in Leadmium Green-loaded wild-type and TRPA1(−/−) mouse DRG neurons. Cells were exposed to Cd (3–300 μM, 4 min) and then TPEN (0.05 mM, 1 min), a cell-permeable heavy metal chelator, was applied at the points shown by arrowheads. Solid and broken lines show the responses in wild-type and TRPA1(−/−) mouse DRG neurons, respectively. (B) The area under the curve of the fluorescent change after the administration of Cd to wild-type and TRPA1(−/−) mouse DRG neurons. Symbols with vertical lines show mean ± SEM. (wild-type; n=112-243, TRPA1(−/−); n=193-382, from 3 mice). *,P <0.05, **,P <0.01 vs. TRPA1(−/−). (C) Solid and broken lines show actual recordings of the changes in the fluorescent ratio induced by Cd in human TRPA1-expresing HEK293 cells (hTRPA1-HEK) and untransfected HEK293 cells (Naïve), respectively.