CHANGES OF ISOENZYMES OF SERUM N-ACETYL-BETA-GLUCOSAMINIDASE IN RELATION TO DIFFERENT TYPES OF DIABETES

The activity of the isoenzymes of N-acetyl-beta-D-glucosaminidase (NAG , EC 3.2.1.30) is determined in the serum of insulin-dependent (IDDM) and non insulin-dependent diabetics (NIDDM) with or without diabetic c omplications. The increase in total activity of serum NAG in diabetics is proportional to the A form activity (r=0,976, p< 0,0001). The cont ribution of the A form activity (65.87+/-5.99%) to total NAG activity of IDDM and NIDDM diabetics with and without complications does not ch ange considerably compared to the control group. The contribution of t he B form activity depends on the state of metabolic monitoring and di abetic complications. A significantly lower activity of the serum B fo rm was found in IDDM (p<0,001) and NIDDM diabetics (p<0,05) compared t o the healthy individuals, as well as the higher activity ratios of th e A/B forms. A decrease in serum B form is correlated with the occurre nce and abundance of the intermediary I forms (r=-0,665). These change s are particularly significant in the individuals with the pronounced microangiopathy.