EFFECTS OF INTERMITTENT OVERPRESSURE IN EAR CANAL ON ENDOLYMPHATIC HYDROPS IN GUINEA PIGS / 解放军医学杂志

ABSTRACT

Intermittent overpressure of 20cmH 2 O was delivered to the external ear canal of guinea pigs. Histopathological changes in the middle and inner ear were examined under light microscope. Auditory evoked potential was recorded. The expression of atrial natriuretic peptide (ANP) was investigated by immunohistochemical SP method. We found that intermittent overpressure could minimize, but could not interrupt the development of endolymphatic hydrops,and could not improve hearing function. Expression of ANP decreased in the cochlear lateral wall after 2 week intermittent overpressure. The results suggested that intermittent overpressure of 20cmH 2 O was suitable in this experiment, and that ANP positive cells had an autocrine/paracrine function.