M. Przybylska et al., CHOLESTEROL SULFATE INDUCES CHANGES IN HUMAN ERYTHROCYTE THERMOSTABILITY, Biochemistry and molecular biology international, 46(2), 1998, pp. 399-410
The influence of cholesterol sulfate (CS) on human red blood cell ther
mosensitivity was studied by flow cytometry and scanning electron micr
oscopy. It was found that the effect of this sterol on erythrocyte sta
bility is biphasic. Exposure of red blood cells (RBC) to the elevated
temperature (51 degrees C) induced perturbation of the cell membrane a
nd led to haemolysis. Preincubation of cells with CS at a concentratio
n of 1 x 10(-5) M protected them, to a certain extent, against lysis.
In contrast, enrichment of RBCs with CS during the incubation with low
er (0.4 x 10(-5) M) or higher (4-8 x 10(-5) M) CS concentrations subst
antially augmented the fragility of the cells. The fact, that at the s
ublytic concentrations CS stabilises the cell membrane, may be explain
ed by the ability of this amphipathic compound to link hydrophilic and
lipophilic domains of the cell membrane and to increase the degree of
the lipid bilayer order. Higher CS concentrations cause cell lysis in
a detergent-like manner. Our data support the conclusion that CS can
be considered to be a potent thermosensitizer, which enhances the sele
ctivity of biological drug carriers.