Effects of hyperglycaemia and sorbitol accumulation on erythrocyte deformability in diabetes mellitus.

Abstract

SUMMARY Erythrocyte deformability was studied in a total of 83 poorly controlled diabetics (mean blood glucose 12-2 mmol/l) who were divided into three groups, each with matched healthy controls. There was no appreciable difference between diabetics and matched controls regarding the filtration of erythrocytes through 3 gum diameter straight channel pores (25 diabetics) or tortuous channel pores (28 diabetics), or for the measurement of erythrocyte elongation over a range of osmolalities in the Ektacytometer (30 diabetics). When erythrocytes from 17 additional diabetics and 17 healthy controls were incubated for two hours at 37°C in hyperglycaemic (50 mmol glucose/l) buffer, however, there was a considerable reduction in erythrocyte filterability for both diabetics and controls in parallel with an increase in erythrocyte sorbitol concentration. This loss of filterability was prevented by the addition of an aldose reductase inhibitor (Sorbinil). High glucose concentrations (-50 mmol/l) impair the filterability of erythrocytes through 3 gm pores, and the intracellular accumulation of sorbitol in poorly controlled outpatients is therefore unlikely to have a major adverse effect on erythrocyte rheology in diabetes mellitus.Erythrocytes from uncontrolled diabetics were originally found to have impaired deformability when suspended in autologous plasma and filtered through 5 gim diameter pores.' It was subsequently suggested that the impaired erythrocyte filterability could be corrected in vivo and in vitro by the addition of insulin.2 Several factors extrinsic to the erythrocyte, however, may contribute to this impairment of filterability in uncontrolled diabetes. These include an acute phase increase in plasma fibrinogen concentration3; leucocytosis4; plasma hyperosmolality,3 5 which can increase erythrocyte mean cell haemoglobin concentration; and a low blood pH6 or low plasma sodium concentration,7 which can increase erythrocyte mean cell volume.The individual rheological effects of these extrinsic factors can be studied by resuspending leucocyte depleted washed erythrocytes in an appropriate buffer. In two earlier studies normal erythrocytes suspended in hyperglycaemic buffer showed impaired filtration through 5 gm diameter pores.8' As water crosses the erythrocyte membrane in milliseconds'0 and glucose loss from the cell has a half life of < 30 seconds," 2 hyperglycaemia of plasma or buffer is unlikely to impair erythrocyte rheology by a simple Intracellular accumulation of sorbitol in diabetics has previously been implicated in the development of cataracts,'6 peripheral neuropathy,'7 and arterial wall lesions.'8 We therefore compared the rheology of erythrocytes from poorly controlled outpatienrt diabetics, with that of matched controls, and we also-, investigated the rheological effect of incubating diabetic and normal erythrocytes in high concen-722 on 11 May 2018 by guest. Protected by copyright.

Investigation of the effects of propofol and vitamin C administration on erythrocyte deformability in rats with streptozotocin-induced

“…The fi ltration technique measurement shows that the erythrocyte deformability is signifi cantly decreased (44)(45)(46)(47). Similar decrease in deformability by ektacytometry (48) and transparent microchannels were observed (49).…”

Molecular Effects of C-Peptide in Microvascular Blood Flow Regulation

“…Thus, reduced erythrocyte elasticity will limit microvascular blood flow, if the capillary diameter and blood pressure remain constant [36]. In patients with diabetes mellitus, several factors such as decreased erythrocyte deformability, increased erythrocyte aggregation, and increased erythrocyte membrane viscosity contribute to erythrocyte dysfunction, and might affect microvascular blood flow and tissue nutrition [16,18,19,[37][38][39]. Impaired erythrocyte function in patients with diabetes mellitus was attributed to the modification of proteins and lipids by advanced glycation endproducts, to the generation of free oxygen radicals, and to changes in ion homeostasis attributed to hyperglycemia [40].…”

The effects of propofol and memantine on erythrocyte deformability

“…The fi ltration technique measurement shows that the erythrocyte deformability is signifi cantly decreased (13)(14)(15)(16)(17). Similar decrease in deformability by ektacytometry (18) and transparent microchannels has been observed (19).…”