Iodide uptake into phagosomes of normal and CF neutrophils. By using the iodide-specific probe, iodide uptakes by phagosomes of normal neutrophils from four donors (•, solid line) or from four CF donors (▪, dashed line) were determined. A decrease rate and extent of iodide uptake were seen in CF neutrophils (▪, dashed line), which was slightly less than that seen in normal cells treated with 20 μM CFTRinh172 (○, solid line). CFTRinh172 did not affect the rate of uptake of iodide by CF neutrophils (□, dashed line).