Update on peripheral mechanisms of pain: beyond prostaglandins and cytokines.

The peripheral nociceptor is an important target of pain therapy because many pathological conditions such as inflammation excite and sensitize peripheral nociceptors. Numerous ion channels and receptors for inflammatory mediators were identified in nociceptors that are involved in neuronal excitation and sensitization, and new targets, beyond prostaglandins and cytokines, emerged for pain therapy. This review addresses mechanisms of nociception and focuses on molecules that are currently favored as new targets in drug development or that are already targeted by new compounds at the stage of clinical trials--namely the transient receptor potential V1 receptor, nerve growth factor, and voltage-gated sodium channels--or both.