Proteoglycans of alveolar bone of diabetic and non-diabetic mice, a histochemical study

Abstract

The effect of diabetes mellitus on the interdental alveolar bone has been long debated. The present study reported the distribution of glycosaminoglycans (GAG) in normal and diabetic alveolar bone using histochemical techniques. Animals were rendered diabetic and killed at 2,4,6 and 9 weeks after injections. Tissues were stained with Alcian blue 8GX dye (pH 2.5) to demonstrate GAG and the intensity of the staining reactions compared with age-matched controls. During the experiment, weights of control animals did not change significantly; weights of diabetic animals were significantly less than initial weights from O- 6 weeks (p<0.001), but became nearly equal by 9 weeks. Staining intensity of diabetic bone demonstrated initial decrease (0-4 weeks) followed by a marked increase (4-9 weeks) suggesting an early decline in bone GAG levels followed by increased bone GAG levels as compared to age-matched control and initial levels. Bone GAG levels were significantly different between diabetics and agematched controls at 2 (p<0.005) 4 (p<0.001), 6 (p<0.001) and 9 (p<0.001) weeks after streptozotocin injections. Digestion with chondroitinase AC, ABC and streptomyces hyaluronidase suggested significant differences between control and diabetic bone matrix in the levels of chondroitin 4 and 6 sulfates (p<0.05) and hyaluronic acid (p<0.001) but not dermatan sulfate. In control and diabetic bone, chondroitin sulfates were located within the bone matrix, dermatan sulfate within bone matrix and Sharpey fiber bundles. Thus, bone GAG changes in diabetes mellitus occur predominately within bone matrix and are variable depending on the length of the disease.