Hemin-Induced Membrane Sulfhydryl Oxidation: Possible Involvement of Thiyl Radicils

Abstract

Sublytic levels (microM) of hemin destabilized RBC membrane as indicated by ghost fragmentation pattern using a laser viscodiffractometer. Furthermore, electron microscopic study shows that 5 microM of hemin induced echinocytic transformation whereas higher hemin concentration (40 microM) induced spherocytic transformation. In addition, hemin oxidized sulfhydryl groups in a dose dependent fashion and Electron Spin Resonance study suggests that such oxidation may involve a thiyl radical. Moreover, sulfhydryl compounds enhanced hemin-induced lipid peroxidation. Desferroxamine could prevent hemin-induced sulfhydryl oxidation as well as hemin-induced decrease in membrane stability. In contrast, vitamin E could effectively prevent hemin-induced lipid peroxidation but could not prevent hemin-mediated membrane destabilization.

Transformation of membrane nanosurface of red blood cells under hemin action

“…Alteration of cell shape after the hemin action, i.e. formation of echinocytes and spheroechinocytes, was detected by a light microscopy7. However, this approach does not allow to show the grain-like structures on the cell membrane.…”

“…The objects of its action in RBC are known. The optical microscopy and electron microscopy showed that hemin causes a formation of echinocytes under low concentrations and spheroechinocytes under high concentrations7. Finally this leads to hemolysis.…”

Nanostructural Changes in the Cell Membrane of Gamma-Irradiated Red Blood Cells

“…Second, denaturation of hemoglobin (Hb) can cause the damage. Accumulating evidence has shown that released hemin, one of the end product of Hb denaturation, is a potent catalyst of lipid peroxidation, which in turn causes hemolysis [27][28][29]. Many microscopy studies have shown that hemin can affect the conformation of the cell cytoskeleton, which in turn affects the cell structure [27,29,30].…”

Free Radical and Oxidative Damage in Human Blood Cells

“…In addition, to promote lipid peroxidation, hemin could affect RBC morphology and destabilize membrane [12], Further study indicated that hemin could oxidize membrane sulfhydryl groups in a dose-dependent fash ion. Our electron spin resonance study suggested that such oxidation may be mediated by a thiyl radical.…”

“…Our electron spin resonance study suggested that such oxidation may be mediated by a thiyl radical. Desferroxamine could prevent hemin-induced sulfhydryl oxi dation as well as hemin-induced decrease in membrane stability [12].…”