Modifications induced by diabetes on the physicochemical and functional properties of erythrocyte plasma membrane.
Increasing evidence suggests that in experimental diabetes an impairment in Na+,K+-ATPase activity plays a central role in the pathophysiology of diabetic complications, while only a few data are available with regard to human subjects. We studied the erythrocyte membrane Na+,K+-ATPase activity and membrane fluidity in insulin-dependent and non-insulin-dependent diabetic subjects. A significant decrease in the enzyme activity and in fluorescence polarization values was found in both groups compared with normal subjects. Neither Na+,K+-ATPase activity nor membrane fluidity was found to be related to metabolic control, assessed by means of fasting blood glucose levels and HbA1c. On the contrary, a significant correlation was observed between Na+,K+-ATPase activity and membrane fluidity in both insulin-dependent and non-insulin-dependent diabetic subjects. The present work provides evidence that a reduction in the Na+,K+-ATPase activity is present in the plasma membranes of insulin-dependent and non-insulin-dependent diabetics. Furthermore, it suggests that the change in enzyme activity might be related to modifications in membrane fluidity.
Mazzanti
L
L
Institute of Biochemistry, University of Ancona School of Medicine, Italy.
Rabini
R A
RA
Testa
I
I
Bertoli
E
E
D000328:Adult; D000368:Aged; D003920:Diabetes Mellitus / Q000097:blood*; D004910:Erythrocyte Membrane / Q000378:metabolism*; D005260:Female; D005454:Fluorescence Polarization; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008297:Male; D008560:Membrane Fluidity; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood; D000254:Sodium-Potassium-Exchanging ATPase / Q000097:blood*
D006442:Glycated Hemoglobin; D011188:Potassium; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase