The determination of phospholipids in middle ear effusion from experimental otitis media in the chinchilla.

Phospholipid types were clarified both in eustachian tube secretion (ETS) and middle ear effusions (MEEs) from chinchilla middle ear. ETS was obtained from normal healthy animals and from animals with experimentally induced purulent otitis media (POM). MEE was obtained from experimentally induced serous and purulent otitis media (SOM and POM). In normal ETS, phosphatidylcholine (36.4%) was predominant followed by phosphatidylethanolamine (30.6%), sphingomyelin (18.0%), phosphatidylinositol (7.2%), phosphatidylglycerol (8.8%) and phosphatidylserine (2.5%). A significant loss of phosphatidylcholine was observed in ETS and MEE from experimentally induced otitis media. These findings suggest that both POM and SOM might be caused by a relative decrease of phospholipids, which is a major component of surfactants. Furthermore, the analysis of phospholipids in MEE may yield baseline information necessary to specify the factors responsible for chronicity or the tendency of recurrence of otitis media.