Influence of streptozotocin- and alloxan-induced diabetes in the rat on collagenase and certain lysosomal enzymes in relation to the degradation of connective tissue proteins.

The activity of collagenase and certain lysosomal hydrolases (cathepsin B1, cathepsin D, beta-glucuronidase and beta-N-acetyl glucosaminidase) was studied in serum and tissues of rats with streptozotocin- or alloxan-induced diabetes. The activity of serum lysosomal enzymes was increased in both groups (p less than 0.05). Both streptozotocin- and alloxan-diabetic animals showed significantly higher dermal collagenase activity than those of controls (p less than 0.01), but the liver and spleen showed similar activities; there was a significant decrease in the renal collagenase activity of streptozotocin-diabetic rats (p less than 0.05). Comparison of the alloxan- or streptozotocin-treated groups with control animals showed an increase in lysosomal enzymes (cathepsin B1, cathepsin D, beta-glucuronidase and beta-N-acetyl glucosaminidase in skin, liver and spleen) (p less than 0.05) but beta-N-acetyl glucosaminidase was unchanged in the spleen of streptozotocin-diabetic rats. There was no difference in renal cathepsin B1 and D in control versus alloxan-diabetic rats, but there was an increase in beta-glucuronidase and beta-N-acetyl glucosaminidase (p less than 0.05). The streptozotocin-diabetic animals showed decreased activities of renal lysosomal enzymes (p less than 0.05), but similar activity of cathepsin D to the control animals.