The biochemical basis of cystic fibrosis: an hypothesis based upon the polyelectrolytes of mucus.

The evidence shows that the pathology of cystic fibrosis (CF) is related 
to mucoid secretions. Consequently, the question of what governs the viscosity 
of mucus is examined in detail. It is generally agreed that 
the mucin gel consists of polyanionic glycoproteins and a hitherto unidentified 
poly cationic cross-linking protein. It is proposed that larger amounts of 
polycations increase viscosity and, in excess, cause mucus to become a 
polycation. As these compounds are known to inhibit the ductal reabsorption 
of sodium, the two principal aspects of the pathology of CF 
can be related to the same mechanism. The mucus globule membrane 
(MGM) has been proposed as the cross- linking protein. 