Abnormal mucus: nominated but not yet elected.

Mucus secretions of the intestine may contribute to plug formation in CF, through several mechanisms acting alone or simultaneously. Excessive mucin secretion and relative dehydration of secretions would elevate mucin concentration and enhance mucus gel formation. Deficient pancreatic enzymes combined with intrinsic hyperglycosylation of mucin or an increase in covalently bound fatty acid groups on mucins, would retard normal proteolytic degradation of mucins. Excessive calcium ions in the ducts would tend to decrease mucin solubility, while excessive hydrogen ions and protein (especially albumin) together with mucins, may be responsible for the appearance of proteinaceous ductal 'plugs' characteristic of CF pathology.