Neuropeptide Y (NPY).

Neuropeptides such as neuropeptide Y (NPY) have long been proposed to play a role in the pathogenesis of inflammatory diseases. NPY is a 36 amino acid neuropeptide which participates in the regulation of a large number of physiological and pathophysiological processes in the cardiorespiratory system, immune system, nervous system and endocrine system. Serum levels of NPY are increased during exacerbations of asthma, whereas the number of NPY-immunoreactive nerves in the airways remains constant in the airways of patients with inflammatory airway diseases such asthma or rhinitis. Next to a role in the regulation of glandular activity, NPY exerts a major influence on humoral and cellular immune functions. In this respect, NPY is known to modulate potent immunological effects such as immune cell distribution, T helper cell differentiation, mediator release, or natural killer cell activation. In addition to these direct effects, NPY also acts as an immunomodulator by influencing the effects of a variety of other neurotransmitters. Whereas the peptide has been focused for therapeutic options in the central nervous system, a potential use in the treatment of pulmonary inflammatory disorders has not been revealed so far due to the complex pulmonary effects of NPY. However, since selective antagonists and agonists and gene-depleted animals for the different receptors are now available, NPY may be of value for future strategies in airway nerve modulation.