Figure 5. The effect of clonidine is reversed by the α2 antagonist yohimbine.

Collected results show the effect of yohimbine (α2 antagonist) on the capsaicin‐activated inward and outward currents. A, representative capsaicin‐activated currents recorded in the presence of 1 μm capsaicin (cap, black trace), after application of 1 nm clonidine (clo) on top of capsaicin (red trace), and upon removal of clonidine (blue trace). B, representative capsaicin‐activated currents recorded in the presence of 1 μm capsaicin + 1 nm yohimbine (yoh, black trace), after application of 1 nm clonidine on top of capsaicin and yohimbine (red trace), and upon removal of clonidine (blue trace). C, the inward current was reduced by 54 ± 10% (n = 6) by 1 nm clonidine and by 8 ± 5% by 1 nm clonidine + 1 nm yohimbine (n = 7), ^** P < 0.01, unpaired t test. D, the outward current was reduced by 40 ± 10% (n = 6) by 1 nm clonidine and by 5 ± 3% by 1 nm clonidine + 1 nm yohimbine (n = 7), ^** P < 0.01, unpaired t test.