Alterations in the activity of several glycohydrolases in red blood cell membrane from type 2 diabetes mellitus patients

The erythrocyte membrane in 71 patients with type 2 diabetes mellitus was assessed for glycohydrolase activity: N-acetyl-β-D-glucosaminidase, β- D-glucuronidase, α- and β-D-galactosidase, α- and β-D-glucosidase, α-D- mannosidase, and α-L-fucosidase. Only β-D-glucuronidase, α-D-glucosidase, and β-D-glucosidase showed markedly elevated levels with respect to the controls regardless of the presence of complications. Among the examined patients, those with good metabolic control (not yet submitted to any therapy) showed the same enzyme levels as the reference subjects, while the levels in patients with unsatisfactory metabolic control (treated with oral hypoglycemic and/or insulin) significantly differed from the control levels. For α-D-glucosidase and β-D-glucosidase, a correlation with glycemia and the parameters of metabolic control was also evidenced. Alterations of β-D- glucuronidase, α-D-glucosidase, and β-D-glucosidase were also ascertained in the plasma of the same diabetic patients according to the literature; each enzyme correlated with the other, either in plasma or in the erythrocyte membrane. This study shows a correlation between plasma and erythrocyte membrane levels for these three enzymes. The strict parallelism of the glycohydrolases in the two different compartments provides a profile of these enzymes in the pathology of diabetes.