Protective effect of pulmonary surfactant on cilia of Eustachian tube in otitis media with effusion.

OBJECTIVE

The aim of this study was to evaluate the effect of pulmonary surfactant (PS) on cilia of Eustachian tube (ET) in guinea pigs suffering from otitis media with effusion (OME).

METHODS

A nonviable heat-killed pneumococci (HKP) solution was injected into the tympanum of guinea pig via a transtympanic approach therefore establishing models of OME (effusion in tympanum and hearing loss). After being injected with physiologic saline solution or pulmonary surfactant transtympanically, the response threshold of each guinea pig was taken by ABR. Changes of effusion and ciliary ultrastructure were observed.

RESULTS

Normal group (A), the response threshold is 14.00+/-3.08 dBHL. Abundant and intact cilia were observed, ciliary morphology was normal, cilia regularly arranged in concord, no goblet cells was observed. Model-control group (B0), 5 days following the inoculation of HKP, serous effusion was present in tympanum. The response threshold is 45.00+/-5.67 dBHL. Cilia lost and arranged irregularly, hyperplasia of the goblet cells was observed. Saline group, the previously observed serous effusion of tympanum was increased or unchanged. The response threshold is 65.50+/-6.85 dBHL. Cilia were coalescing and swelling. A lot of cilia lost and arranged disorderly. A number of compound cilia of the bulging type were formed by cytoplasmic protuberances of ciliated cells. Massive mucoid secretions stuck on the surface of the ET. PS group, the previously observed serous effusion of tympanum was reduced in amount or disappeared completely. The response threshold is 23.53+/-6.32 dBHL. Ciliary morphology was generally normal. Cilia comparatively arrange in concord. A mucus deposits was adhering to the tips of cilia.

CONCLUSION

The findings of the study suggest that pulmonary surfactant plays an important role in protecting of cilia of ET of guinea pigs suffering from OME.