Vasoactive intestinal peptide immunoreactive nerve fibres are deficient in intestinal and nasal mucosa affected by cystic fibrosis

Cystic fibrosis (CF) is the most common lethal or debilitating inherited disease amongst Caucasians, with estimates of its frequency of occurrence in this population ranging from 1: 2000 to 1: 15 000 live births. It is characterized by disorders of exocrine secretions, primarily of the skin, respiratory tract and digestive system. The secretory processes of these tissues are influenced by autonomic nerve fibres, many of which contain regulatory peptides. The innervation of the intestinal and respiratory mucosa of CF patients has been investigated in order to determine if there is any derangement of the peptide‐containing nerve fibres that supply these tissues. The present work demonstrates that, in CF, there is a deficiency of vasoactive intestinal peptide immunoreactivity (VIP‐IR) in nerve fibres in the nasal and intestinal mucosa. There is not a generalized loss of fibres that are immunoreactive for this peptide, however, since VIP‐IR fibres innervating the intestinal muscle are largely unaffected. Moreover, other types of nerve fibres innervating the nasal mucosa and the mucosa of the intestinal villi appear to be unaffected in CF patients. Physiological evidence indicates that vasoactive intestinal peptide is contained in secretomotor neurons and is a powerful stimulant of secretion; loss of function restricted to these neurons is consistent with the clinical manifestations of CF.