Figure 5.

Piperine produces a greater degree of desensitisation than capsaicin. The effects of piperine and capsaicin on TRPV1 desensitisation and tachyphylaxis were compared using a repeated applications protocol. Representative traces showing the typical profile of responses obtained during eight repeated applications of (a) 1 μM capsaicin (closed bar) or (b) 100 μM piperine (open bar) are shown. (b) Agonists were applied for 20 s with intervening washout periods of 1 min (indicated by the gaps). (c) The pooled data from the experiments described in (a and b) are given. Agonist responses are expressed as a percentage of the initial current for each of eight repeated applications of capsaicin (n=7) or piperine (n=8). ^*P<0.05; ^**P<0.01 versus the corresponding capsaicin-mediated response.