Potential therapeutic targets for neurokinin-1 receptor antagonists.

The peptide substance P and its tachykinin receptor, neurokinin-1 (NK1), have been the focus of considerable research for their role in a variety of both central and peripheral diseases. Recent preclinical data, as well as relevant clinical findings, support the potential therapeutic value of NK1 receptor antagonists in centrally mediated disease states, including anxiety and depression. In addition, a separate body of literature supports the use of NK1 receptor antagonists as inhibitors of centrally mediated emetic and cough responses. The role of NK1 receptor antagonists as analgesic agents with potential to treat migraine headache has also been investigated. NK1 receptors are also found in a number of peripheral regions, including the bladder, gastrointestinal tract and bone marrow. Preclinical models have been employed to address the potential therapeutic uses for NK1 receptor antagonists in diseases associated with inflammatory responses, including asthma, irritable bowel syndrome and cystitis of the bladder. Finally, other more recent publications suggest a role for NK1 receptor antagonists as tumour suppressants and haematopoietic agents. These applications for NK1 receptor antagonists are discussed in this review.