Bu. Raess et al., EFFECTS OF 4-OH-2,3-TRANS-NONENAL ON HUMAN ERYTHROCYTE PLASMA-MEMBRANE CA2+ PUMP AND PASSIVE CA2+ PERMEABILITY, Biochemical and biophysical research communications, 235(3), 1997, pp. 451-454
Structural and functional alterations of cell membranes caused by free
radicals leading to lipid peroxidation and increases in intracellular
Ca2+ concentrations have been implicated in atherogenesis. The object
ive of this study was to directly measure the effects of a major aldeh
ydic lipid peroxidation product, 4-OH-nonenal (HNE), on plasma membran
e Ca2+ regulatory mechanisms. This was attained by measuring passive C
a2+ permeability, primary active Ca2+-transport, and (Ca2++Mg2+)-ATPas
e activity in a human red cell model system. Using this three-pronged
approach it could be shown that HNE increases passive Ca2+ permeabilit
y significantly beyond the typically low basal flux, while at the same
time inhibiting the active Ca2+ extrusion pump and associated (Ca2++M
g2+)-ATPase activity. We conclude that this deleterious combination of
effects by HNE in this plasma membrane model system may be indicative
of plasma membrane changes in cells directly involved in atheroma for
mation and thus may represent causative factors in the early stages of
atherogenesis. (C) 1997 Academic Press.