Permeability of round window membrane to human serum albumin in chinchillas

Abstract

The round window membrane (RWM) permeability to human serum albumin (HSA) was investigated in sensitized chinchillas with HSA (Arthus otitis media). The effect of a corticosteroid agent (Triamcinolone) on the RWM permeability was also studied. HSA could not be detected in either the perilymph (PL) and CSF of normal chinchilla within 1hr after instillation into the middle ear bulla. However, significant level of HSA could be quantified in the PL of which peak was observed at 24 hrs after instillation. In sensitized chinchillas, HSA level in the PL at 12 hrs after instillation was significantly higher than that of normal chinchilla (p<0.01), and had large individual variations after 24 hrs. HSA levels in the PL significantly decreased by a steroid treatment (p<0.025 at 24 hrs and p<0.05 at 48 hrs). It is concluded that only a small amount of HSA could pass through the normal RWM for a short time, and certain period of time is necessary for HSA to pass, and that the RWM permeability to HSA increases in the early stage of Arthus otitis media (about 12 hrs) and has large variations with the development of Arthus otitis media. A corticosteroid agent reduces the passage of HSA by suppressing the degree of Arthus otitis media.