Effects of glycerol on the thermal dependence of the stability of human erythrocytes

Abstract

Incubation of human blood in saline solution of 0-36% (v/v) ethanol for 30 min produces lysis or stabilization of erythrocytes depending on the ethanol concentration. Under less elevated concentrations of ethanol, erythrocytes are present in expanded shapes (R state) that present lower stability and suffer lysis with increase in the ethanol concentration. Under more elevated concentrations of ethanol, erythrocytes are present in contracted shapes (T state) that have higher stability and suffer lysis at even more elevated ethanol concentrations. This work evaluated the effects of glycerol (0 to 2.0 M) and temperature (7 to 47 degrees C) on the stability of the R erythrocytes, characterized by the ethanol concentration at the mid-transition point (D (50R )) of the hemolysis curve (D (50R )). D (50R ) declined sigmoidally with increase in the glycerol concentration or temperature, due to transition of the R to the T state erythrocytes. In 1.5 M glycerol, the erythrocytes stability decreased below 32 but increased above 37 degrees C. The combination of temperature, glycerol and ethanol actions generates a critical value of osmotic pressure below which the R state predominates and above which the T state predominates. At 7 degrees C 1.5 M glycerol decreased the erythrocytes stability against ethanol but increased the erythrocytes stability against hypotonic shock. Those conditions favor the R state, which has a lower stability against ethanol; however, in the absence of ethanol, glycerol determines less water entrance in the erythrocytes, making more difficult its lysis by hypotonicity.

Influence of Glucose Concentration on the Membrane Stability of Human Erythrocytes

“…After addition of 20 ll of blood aliquots to the tubes, they were capped, gently mixed, and incubated at 37°C for 30 min, before being centrifuged at 15009g for 10 min. The erythrocytes lysis was followed by measuring absorbance of the supernatants at 540 nm (A 540 ) [7,8].…”

“…It is defined as the capacity of the biological complex in keeping its structure against chaotropic conditions. Among the various homeostatic mechanisms that nature uses to preserve the stability of biological complexes is the control of the osmolarity of the medium by the action of solutes collectively referred to as osmolytes [1][2][3][4][5][6][7][8].…”

“…This experimental model have been used to study the influence of solutes such as ethanol, glycerol and sorbitol [7,8], natural products [24], detergents [25][26][27], and degenerative processes [28][29][30] on the stability of erythrocyte membrane.…”

“…In this study, we studied the in vitro influence of different glucose concentrations on the stability of human erythrocytes. Since a stabilizing effect was observed, the possible origin of this effect was examined in the light of what is known about the effects of osmolytes on the stability of erythrocytes [7,8] and about the influence of glucose on the rheological properties of these cells [31,32].…”

Effects of Roundup® Pesticide on the Stability of Human Erythrocyte Membranes and Micronuclei Frequency in Bone Marrow Cells of Swiss Mice

“…A test, which is a variation of EOF, is the measure of the stability of erythrocyte membranes in physiological saline solution under a concentration gradient of the chemical agent to be evaluated [19,22,23].…”