The biologic activities of cystic fibrosis serum. I. The effects of cystic fibrosis sera and calcium ionophore A 23187 on rabbit tracheal explants.

An ionophore A23187-induced increase in membrane permeability to calcium ions in culture 
medium produced a rabbit tracheal mucociliary response indistinguishable from that caused 
by cystic fibrosis (CF) sera on three different occasions. Specific chelation 
of calcium ions with EGTA in the basal medium Eagle (BME) 
media with no additive or in native CF sera abolished the 
mucociliary disturbances in all cases. Increased membrane permeability to calcium may 
be important in the production of the mucociliary response by CF 
serum factor(s) in the tracheal assay system. 