Hypertonic saline decreases ciliary movement in human nasal epithelium in vitro

Various saline solution formulae are frequently used in patients with rhinosinusitis. Osmolarity affects ciliary beat frequency (CBF); however, little is known about the effects of saline solutions on ciliary activity of nasal epithelial cells. The aim of this study was to assess whether CBF of normal turbinate mucosa is affected by hypertonic, isotonic, or hypotonic saline solution in vitro and whether histologic changes are associated with the alteration of ciliary movement. We assessed variations of CBF after exposure to 0.06%, 0.12%, 0.9%, 3.0%, or 7.0% saline solutions and histologic changes were examined by transmission electron microscopy. Isotonic and hypotonic solutions produced no ciliary slowing; however, ciliostasis was observed within a few minutes in 3.0% or 7.0% solution. The histologic changes demonstrated that the ciliary slowing might be attributed to epithelial damage by fluid transport toward the surrounding medium. In conclusion, hypertonic saline solutions decrease CBF and disrupt nasal epithelial cells in vitro.