Modifications of liver lysosomes in diabetic rats.

Recently investigators reported ultrastructural modifications of rat liver lysosomes which probably correlate with an increased level of blood plasma glucagon in streptozotocin-diabetes. We are investigating whether biochemical changes occur in this condition. Lysosome fragility is increased in the hepatocytes of streptozotocin-diabetic rats. Moreover the plasma activity of two glycosidases, B-N-acetylglucosaminidase and B-galactosidase, is markedly increased in streptozotocin-treated rats. Both these changes are largely prevented by insulin treatment. These findings support the idea that the morphologic and biochemical modifications of the hepatocytes, which are observed in experimental diabetes, involve the lysosomes showing an increased autophagic activity which is probably connected with enhanced liver protein catabolism.