Effects of alkanols, alkanediols and glycerol on red blood cell shape and hemolysis

Abstract

The physicochemical effects of a series of alkanols, alkanediols and glycerol on erythrocyte shape and hemolysis at 4 and 20 degrees C were examined. We calculated the dielectric constant of the incubation medium, Ds, and the dielectric constant of the erythrocyte membrane Dm in the presence of organic solutes. The ratio Ds/Dm = -38.48 at 20 degrees C defines the normal biconcave shape in a medium without hemolytic agents. A decrease in Ds/Dm favors externalization or internalization with consequent hemolysis. Alkanols and alkanediols convert biconcave erythrocytes into echinocytes, which is accompanied by an increase in the projected surface area. Glycerol converts biconcave erythrocytes into stomatocytes, which was accompanied by a marginal decrease in the projected surface area. Progressive externalization in alkanols and alkanediols or internalization in glycerol resulted in a decrease in the projected surface area and the formation of smooth spheres. The degree of shape change induced was related to the degree of hemolysis and the ratio Ds/Dm. A decrease in temperature reduced both the degree of shape change and hemolysis. Our results suggest that physicochemical toxicity may be a result of a temperature dependent hydrophobic interaction between the organic solutes and the membrane and is best interpreted by the ability of the solutes to change Ds and Dm. These results are discussed with respect to the physicochemical constants of the organic solutes.

Influence of Glucose Concentration on the Membrane Stability of Human Erythrocytes

“…An increase in the osmotic stability of erythrocytes was previously associated to increase in the osmolarity of the medium by incorporation of solutes considered as stabilizing agents, such as glycerol and sorbitol, and even a chaotropic solute, such as ethanol [7,8]. Since such stabilization effect occurs with volume contraction that can be reverted after dilution of the solute excess [21,[38][39][40], this fact was used in the proposition of an equilibrium model between two morphological states of erythrocytes [7,8]. On one hand, in medium with lower osmolarity, there would be cells with expanded volume, which would constitute the morphological state R (relaxed), similar to the R state of hemoglobin.…”

Effects of glycerol and sorbitol on the thermal dependence of the lysis of human erythrocytes by ethanol

“…Modifications in the internal medium are responsible for shape and property changes in erythrocytes [26]; sickle cell anemia and other hemoglobinopathies are living proof of this fact. Changes in the membrane composition also alter the area and the spontaneous curvature of the lipid bilayers [27][28][29]. The increase in stability in the membranes of erythrocytes with aging [30] may be a consequence of changes in their composition.…”

“…The composition and physicochemical properties of the external medium also affect the conformation [20,28,31] and properties [32][33][34][35] of the erythrocyte membrane. Glycerol converts biconcave erythrocytes into cells with membrane internalizations (stomatocytes).…”

“…Ethanol converts biconcave erythrocytes into cells with externalizations (echinocytes). Both of these solutes decrease the surface area with the formation of smooth spheres [28].…”

Anticlotting membrane based on polypropylene grafted by biocompatible monomers under UV irradiation

“…After a centrifugation treatment, the earlier liquids were drawn in cuvettes, and the corresponding absorbance was measured through an ultraviolet-visible spectrophotometer (UV-2100, Shimadzu, Japan) with a wavelength of 545 nm. The hemolysis degree was calculated by the following formula 31,32 :…”