ABSTRACT
The introduction of specific neuropeptide antagonists revolutionize understanding of neural effects in human disease. This approach has been foreshadowed by the widespread use of cholinergic and adrenergic blocking agents that led to the "discovery" of nonadrenergic, noncholinergic actions of nerves. Neuropeptide actions are limited by the enzyme neutral endopeptidase (NEP). Destruction of NEP activity may lead to prolonged, unopposed inflammatory effects of neuropeptides and may contribute to respiratory hyperresponsiveness that can develop in some inflammatory rhinitic conditions. Nociceptive sensory nerve stimulation leads to central recruitment of parasympathetic reflexes. Sympathetic reflexes have been poorly studied, yet probably play a crucial role in the normal homeostasis of nasal mucosa and the responses to exercise and other stresses that require a patent nasal airway. The wave of depolarization releases colocalized combinations of neuropeptides from neurosecretory swellings that are found near glands and vessels.
