Figure 3. Inhibition of N-type Ca currents by eugenol in C2D7 cells. (A) RT-PCR analysis shows no endogenous expression of TRPV1 in C2D7 cells (lane -). TRPV1 is clearly expressed in C2D7 cells following transient transfection (lane +), and in both DRG and TG neurons. The expected size of PCR product was 536 bp. Lane C indicates no PCR products with H₂O. (B) Time course of the effect of eugenol (1 mM) on I_Ba in C2D7 cells which have no endogenous TRPV1 expression (n = 5). (C) Superimposed I_Ba evoked by a test pulse at the points indicated in (B). (D) The summary of I_Ba inhibition in TG neurons and C2D7 cells. The I_Ba inhibition by eugenol in C2D7 cells was significantly greater than that in TG neurons (mean ± SEM, *p < 0.01). The number in parentheses represents the number of cells studied.