Microrheologic investigation of erythrocyte deformability in diabetes mellitus

Abstract

This study was undertaken to determine whether diabetes alters the viscoelastic properties of erythrocytes. The oldest and youngest 10% fractions of circulating red cells were separated by centrifugation of freshly drawn blood obtained from ten diabetics with disease of one to 20 years' duration and from an equal number of age- and sex-matched control subjects. Cells from each fraction were suspended in phosphate- buffered saline, and their rheologic behavior was examined in a rheoscope. The elongation of cells, the percentage of cells that tank- treaded in response to shear stress, tank-treading frequency, and the rate of recovery of cell shape upon cessation of shear stress were determined in the oldest and youngest 10% of cells for diabetics as well as for controls. All four parameters were virtually identical for diabetics and controls. Additional aliquots of cells were taken for assessment of nonenzymatic glucosylation of hemoglobin and cell membrane protein. The absence of any measurable difference in rheologic behavior of cells from diabetic and control subjects, despite substantial differences in nonenzymatic glucosylation of hemoglobin and cell membrane proteins, suggests that the magnitude of glucosylation observed in these cellular constituents does not alter the viscoelastic properties of the cells. The implication of these observations is that microvascular complications of diabetes are not attributable to altered deformability of red cells.

Radiofrequency treatment alters cancer cell phenotype

“…Alterations of mechanical properties of individual cells can reveal important information about changes in these networks. Studies of a variety of diseases utilizing different experimental techniques have shown that abnormalities in the elastic properties of individual cells are important in tissue homeostasis, cell growth, division and motility 37 and is also associated with disease pathogenesis and progression 38 39 40 41 42 . For example, as cells transform from non-malignant to cancerous phenotype, their cytoskeletal structure changes from an organized to an irregular network, and this change subsequently reduces the stiffness of these cells 25 .…”

Mechanisms of C-peptide-mediated rescue of low O2-induced ATP release from erythrocytes of humans with Type 2 diabetes

“…Incubation of DM1 erythrocytes with either C-peptide or insulin has been shown to improve both Na ϩ /K ϩ -ATPase activity and erythrocyte deformability (20,29,31). In DM2, impaired erythrocyte deformability remains controversial, as several groups have observed reduced deformability, while other reports do not confirm this finding (8,48). Although coadministration of C-peptide with insulin at a 1:1 ratio (1 nM of each peptide) rescues low O 2 -induced ATP release from DM2 erythrocytes, the 1:1 ratio had no effect on DM2 erythrocyte deformability (38).…”

Optical Deformability as an Inherent Cell Marker for Testing Malignant Transformation and Metastatic Competence

“…All of the tasks performed by cytoskeletal elements are finely tuned, regulated, and synchronized with the overall function of a specific cell. Consequently, changes to cellular function during differ-entiation (Olins et al, 2000) or due to disease are mirrored in the cytoskeleton: Cytoskeletal alterations cause capillary clogs in circulatory problems (Worthen et al, 1989) and various blood diseases including sickle-cell anemia, hereditary spherocytosis, or immune hemolytic anemia (Bosch et al, 1994;Williamson et al, 1985), and genetic disorders of intermediate filaments and their cytoskeletal networks lead to problems with skin, hair, liver, colon, and motor neuron diseases such as amyotrophic lateral sclerosis (Fuchs and Cleveland, 1998;Kirfel et al, 2003).…”