Involvement of transient receptor potential vanilloid subfamily 1 in endothelin-1-induced pain-like behavior

Although local administration of endothelin-1 (ET-1) is known to evoke spontaneous pain, the mechanism of ET-1-induced pain has not been elucidated. We investigated the involvement of protein kinase C (PKC) and transient receptor potential vanilloid subfamily 1 (TRPV1) in ET-1-induced pain-like behavior. Intraplantar ET-1 evoked pain-like behaviors, including licking, flinching, and biting, in a dose-dependent manner in wild-type mice. ET-1-induced pain-like behavior was attenuated by an endothelin type A receptor antagonist but not by PKC inhibitors and was also attenuated in TRPV1-deficient (KO) mice. In addition, we found a significant reduction of spinal Fos expression caused by the same dose of ET-1 in KO mice compared with that in wild-type mice. This study showed that endothelin type A receptor and TRPV1 are involved in ET-1-induced pain-like behaviors but failed to reveal the contribution of PKC. NeuroReport 20:233-237 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.