Differential effects of TRPV1 antagonist AMG-517 on activation of nociceptive skin endings

The transient receptor potential vanilloid 1 (TRPV1) is a polymodal ion channel activated by capsaicin, protons, and heat. It is predominantly expressed in the peripheral endings of small-diameter nociceptive primary afferent neurons. The localization of TRPV1 receptors in nociceptors and their ability to respond to various damaging stimuli make them a promising target for analgesic therapy. In this work, we studied the effect of the selective TRPV1 antagonist AMG-517 on skin-nerve responses to capsaicin and heating in the mouse using an ex vivo skin-nerve preparation. Topical application of AMG-517 effectively suppressed capsaicin-induced nerve activity but only partially attenuated heat-induced responses. These findings suggest that while TRPV1 plays a key role in the capsaicin-induced activation of nociceptors, thermal sensitivity may involve additional mechanisms beyond TRPV1, emphasizing the need for broader-target therapeutic approaches.