Cochlear vascular changes in streptozotocin diabetes in chinchillas.

Chinchillas were made diabetic by streptozotocin intraperitoneal injection, and the cochlear blood vessels were studied using surface preparation techniques after 3, 6, and 12 months of established diabetes. The following findings were reported: (1) a decrease of alkaline phosphatase activity in the walls of cochlear capillaries after six months of established diabetes, (2) a generalized involvement of the cochlear microcirculation as evidenced by the decrease in alkaline phosphatase activity and by narrowing and irregularities of the capillary lumen, and (3) areas of complete capillary closure in the stria vascularis of the basal turn after 6 and 12 months of established diabetes.