Defective epithelial ion transport in cystic fibrosis.

In America, cystic fibrosis (CF) is the most common fatal inherited disease. In the past few years new concepts have evolved regarding the etiology of CF, changing from an almost universal acceptance of the abnormality as a disease of abnormal mucus production to that of a disease of abnormal fluid and electrolyte transport. Although mucus production is increased, this probably occurs as a secondary defense or protection against more primary disturbances in electrolyte transport brought on by a defect in Cl- permeability that affects both fluid absorption and fluid secretion. Here I review the progress that has been made and some of the puzzles uncovered in recent investigations of electrolyte transport in secretory and absorptive processes in cystic fibrosis.