Hemolysis of rabbit erythrocytes in the presence of copper ions

Abstract

The hemolysis of red blood cells (RBC) induced by Cu(II) is modified by ceruloplasmin (Cp) and albumin. The time course of hemolysis for rabbit RBC by Cu(II) consisted of two parts, an induction period followed by a catastrophic lysis period. The induction period decreased and the lysis rate increased with increasing Cu(II) concentration. Cp or albumin, modified Cu(II) induced hemolysis, by increasing the duration of the induction period and decreasing the overall rate of hemolysis of RBC. The catastrophic lysis period coincided with a sharp increase in the formation of metHb within the cell and in a rapid uptake of Cu(II). The presence of Cp led to an increase in the induction period prior to the rapid increase in metHb formation and in Cu(II) uptake. Porcine Cp was prepared with either two or three nonprosthetic copper binding sites (sites where Cu(II) is easily removed by passing over Chelex-100). Cp with three nonprosthetic binding sites gave more protection than Cp with two. Likewise, albumin can be prepared with three and five nonprosthetic copper binding sites. The albumin with five sites gave more protection than the albumin with three sites.

Electrochemical and Conformational Consequences of Copper (CuI and CuII) Binding to β‐Amyloid(1–40)

“…Under our experimental conditions complexation of copper by Ab diminish the RBC haemolysis, in a similar way as binding of copper to albumin and ceruloplasmin decreased rates of the RBC A C H T U N G T R E N N U N G haemolysis. [66] However, prolonged incubation with the cells causes gradual haemolysis; this is consistent with fluorescence and voltammetric data implicating that Ab-Cu complexes still possess oxidative properties. In contrast, fibrillar Ab did not demonstrate this protective function, and induced haemolysis similar to that of unbound copper ions.…”

“…[41] Hydrophobicity assay: Exposure of Ab hydrophobic surface was measured as an increase of bisANS fluorescence resulting from binding to the Ab-copper complex. [66] A ratio of Ab to metal ions was 1:5 (mol/mol). 2 10 À5 m of the peptide and 2 10 À4 m of bisANS concentrations were applied.…”

Identification of S100b Protein as Copper-binding Protein and Its Suppression of Copper-induced Cell Damage

“…In relation to the suppression of copper-induced cell damage by S100b protein, it should be noted that serum albumin, known to tightly bind copper ions (19), likewise exerts inhibitory effects on various oxidative processes involving copper ions. Among such processes are L-ascorbate oxidation catalyzed by copper salt (20) and the hemolysis induced by copper salt alone (12) or by copper salt plus Lascorbate (21).…”

“…Then they were spun down and washed twice with phosphate-buffered saline. The percent hemolysis of the erythrocytes (1.5% hematocrit) in phosphate-buffered saline was determined essentially as described by Caffrey et al (12). The absorbance at 410 nm for osmotically hemolyzed cells was compared with that for copper-induced hemolysis of cells.…”