The cochlea of the spontaneously diabetic mouse. I. Electron microscopic observation of KK mice.

We examined the cochleae of the spontaneously diabetic KK mice by using transmission electron microscopy. At the age of 3 months, the mice started to show evidence for glycosuria and hyperglycemia, and tissue sections showed beginning cochlear pathology. The pathological changes present were found to be limited to the stria vascularis: protrusions of marginal cells, swellings of intermediate cells and widening of intercellular spaces were the main findings seen. These changes progressed with age, but were not observed in age-matched non-diabetic 57BL/6 mice. The possible mechanism of diabetes causing cochlear pathology is discussed.