Abstract
To study the possible involvement of diabetes mellitus in the hearing organ, the cochlea of the NOD (a new animal model of juvenile diabetes mellitus) was examined electronmicroscopically.
The main pathological changes were observed in the vascular stria. The marginal cells degenerated, protruding into the endolymphatic space, and swelling of the intermediate cells was also observed. However, the capillaries in the stria remained fairly normal.
In the basal turn of the cochlea, the organ of Corti also showed pathological changes. The outer hair cells were lost only leaving the cuticular lamina.
In general these findings were similar to those of the KK mouse (another diabetic animal). The degree of degeneration of the cochlea was severer in the present animal. It was most likely that the diabetes mellitus involved the cochlea, especially the vascular stria, where active glucose utilization takes place, through the impairment of glucose metabolism.
