Many of the metallic implants used in orthopaedics are made of stainless steel or cobalt-chromium alloys which contain 18-30% chromium. Hexavalent chromium (Cr VI) has been shown to be the predominant form of chromium released following in vivo and in vitro corrosion of these metal implants (Merritt and Brown, 1995 K. Merritt and S.A. Brown, J. Biomed. Mater. Res. 29 (1995), pp. 627-633. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (67)Merritt and Brown, 1995). Blood chromium levels may be elevated between 50 and 250 times in patients with metal hip implants (Lhotka et al., 2003). At physiological pH, Cr (VI) exists predominantly as the chromate anion and as such can enter cells via non-specific anion channels. The anionic Cr (VI) diffuses readily through the red blood cell (RBC) membrane and is bound by the haemoglobin probably after its rapid reduction to the cationic trivalent state within the RBC (Gray and Sterling, 1950). The aims of this study were to investigate the effect of the presence of chromium in RBCs on oxygen uptake capacity of blood [oxyhaemoglobin saturation (O2-SAT) at specific pO2 values] and to evaluate the suitability of the two commonly used anti-coagulants, heparin and EDTA, for oxygen uptake studies.
- red blood cells