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.