Effects of Saline Solution on Ciliary Movement in Human Nasal Epithelium in vitro

ABSTRACT

BACKGROUND AND OBJECTIVES: Osmolarity is known to affect ciliary beat frequency (CBF) ; however, little is known about the effects of saline spray or irrigation on ciliary activity in human nasal epithelium. The aim of this study was to assess whether CBF is affected by hypertonic, isotonic or hypotonic saline solution in vitro and whether histologic changes are associated with the alteration of ciliary movement. MATERIALS AND METHODS: Normal turbinate mucosa was exposed to five different concentrations including 0.06%, 0.12%, 0.9%, 3.0%, and 7.0% of phosphate-buffered saline solutions. CBF was measured up to 60 minutes after exposure to each concentration of saline solution and histologic changes were examined by transmission electron microscopy. RESULTS: Isotonic and hypotonic saline solutions produced no ciliary slowing ; however, ciliostasis was observed within a few minutes in 3.0% or 7.0% saline solution. Immediately after complete ciliostasis in the hypertonic solutions, the solutions were replaced with 0.12% or 0.9% saline solution in order to observe the reversibility of CBF. Only 0.12% hypotonic saline induced the recovery of ciliary movement. The ultrastructural changes demonstrated that the ciliary slowing might be attributed to epithelial damage by fluid transport toward the surrounding medium. CONCLUSION: Our results suggest that isotonic and hypotonic saline solutions may be more appropriate for nasal irrigation than hypertonic saline solutions.