Influence of middle ear effusion on perilymph

To investigate the influence of middle ear effusion (MEE) on perilymph (PL), an experimental otitis media with effusion (OME) was provoked in chinchillas by injecting the tympanic cavity with immune complexes. MEE remained for up to 9 days after the injection of immune complexes. PL was aspirated on the 4th, 10th, and 21st day after the inoculation. The mean concentrations of albumin, IgG, and prostaglandin E2 (PGE2) were significantly greater in PL from OME induced ears than in that form normal control ears. 3H-PGE2 placed on the round window membrane of pathologically affected ears passed into PL in significantly greater amounts than in normal controls. The findings of the present study indicate that MEE affects the biochemical environment of PL. However, this influence was transient and reversible.