Neuropeptides in tendinopathy.

Overuse tendinopathy remains a major clinical burden for sports medicine and general practitioners. Recent studies have highlighted the role of sensory and autonomic nerves in generating or perpetuating the symptoms and tissue abnormalities associated with tendinopathy. We outline the neuroanatomy and potential roles of nerves and associated neuropeptides in tendinopathy. In addition, intriguing new data is reviewed which suggests that there may be a substantial intrinsic source of neuropeptides within tendons - namely, the tenocytes themselves. The potential roles of Substance P and mast cells are highlighted in particular. We discuss the implications for conservative management including sclerosing injections and exercise training.