A morphometric study of submandibular salivary gland changes in streptozotocin-induced diabetic rats.

The morphology of the glands in 9 male rats was studied after 3 months of streptozotocin-induced diabetes mellitus and compared with that of 9 control rats and 6 streptozotocin-treated, non-diabetic rats which served as controls for any effect of streptozotocin not due to diabetes mellitus. In the diabetic group, mean salivary-gland weight and volume was reduced. There was an increase in the ratio of mean volume to total gland volume for seromucous acini (p less than 0.01), intra-lobular striated ducts (p less than 0.001), fat (p less than 0.001) and blood vessels (p less than 0.01), and a decrease in both granular duct (p less than 0.001) and intercalated duct (p less than 0.01) volume ratios. There was a marked reduction in the total length of granular ducts (p less than 0.001) and an increase in the length of striated ducts (p less than 0.001). Measurements from the streptozotocin-treated, non-diabetic group did not differ significantly from those of controls. These effects may be attributable to failure of growth and chronic sodium depletion.