Figure 2
From: Cutaneous nociception evoked by 15-delta PGJ2 via activation of ion channel TRPA1
15d-PGJ 2 activates TRPA1, but not TRPV1 or TRPM8, expressed in HeLa cells. A. Whole-cell current was recorded at a membrane potential of -40 mV (n = 3). B. A cell-attached patch shows activation of TRPA1 by 15d-PGJ2. Pipette potential was held at -60 mV to record outward current (n = 4). 15d-PGJ2 increased the channel activity (NPo) from a basal level of 0.03 ± 0.01 to 2.10 ± 0.30. C. A cell-attached patch shows activation of TRPA1 by 15d-PGJ2 and AITC. Pipette potential was held at +40 mV to record inward current. The bars in the graph represent the mean ± SD of 4 determinations, and are significantly different from each other. The channel activity (NPo) elicited by AITC was 6.6 ± 1.4. D-E. In HeLa cells expressing TRPV1 or TRPM8, 15d-PGJ2 had no effect, whereas capsaicin or menthol respectively, activated TRPV1 or TRPM8 (n = 4). Pipette potential was held at -40 mV. The large activation for TRPV1 by capsaicin could not be recorded at the amplifier gain setting used to show the lack of effect of 15d-PGJ2, but full washout was always observed following removal of capsaicin.