Changes in permeability of strial vessels following vibration given to auditory ossicle by drill.

We produced drill-induced damage of the auditory ossicles of guinea pigs to study changes over time in the permeability of the blood vessels of the stria vascularis to horseradish peroxidase (HRP). In group A, the stimulus was applied for 10 seconds after intravenous injection of HRP. In group B, it was applied for 30 seconds, and in group C, for 60 seconds. The cochlea was fixed with 2% glutaraldehyde perfused through the round window, and the guinea pigs were then decapitated. The stria vascularis of the basal and third turns was examined. The leakage of HRP from the blood vessels of the stria vascularis significantly increased in relation to the duration of the stimulus in both the basal and third turns. The damage to intermediate cells also tended to be in relation to the duration of the stimulus. Extravascular permeation of HRP took place through the tubules in the endothelial cytoplasm. The vibratory stimulation presumably opened channels that are not normally open.