Changes of isoenzymes of serum N-acetyl-beta-glucosaminidase in relation to different types of diabetes

Abstract

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 complications. The increase in total activity of serum NAG in diabetics is proportional to the A form activity (r=0,976, p lt 0,0001). The contribution of the A form activity (65.87+/-5.99%) to total NAG activity of IDDM and NIDDM diabetics with and without complications does not change considerably compared to the control group. The contribution of the B form activity depends on the state of metabolic monitoring and diabetic complications. A significantly lower activity of the serum B form was found in IDDM (p lt 0,001) and NIDDM diabetics (p lt 0,05) compared to the healthy individuals, as well as the higher activity ratios of the A/B forms. A decrease in serum B form is correlated with the occurrence and abundance of the intermediary I forms (r=-0,665). These changes are particularly significant in the individuals with the pronounced microangiopathy.