Chloride channels and cystic fibrosis of the pancreas.

Cystic fibrosis (CF) affects approximately 1 in 2000 people making it one of the commonest fatal, inherited diseases in the Caucasian population. CF is caused by mutations in a cyclic AMP-regulated chloride channel known as CFTR, which is found on the apical plasma membrane of many exocrine epithelial cells. In the CF pancreas, dysfunction of the CFTR reduces the secretory activity of the tubular duct cells, which leads to blockage of the ductal system and eventual fibrosis of the whole gland. One possible approach to treating the disease would be to activate an alternative chloride channel capable of bypassing defective CFTR. A strong candidate for this is a chloride channel regulated by intracellular calcium, which has recently been shown to protect the pancreas in transgenic CF mice. Pharmacological intervention directed at activating this calcium-activated Cl- conductance might provide a possible therapy to treat the problems of pancreatic dysfunction in CF.