Enhanced bilirubin binding to different mammalian erythrocytes in the presence of magnesium ions.

Effect of magnesium ions on the binding of bilirubin to erythrocytes of different mammalian species, namely, human, buffalo, goat and sheep was studied. Increase in the concentration of magnesium ions led to a gradual increase in the erythrocyte-bound bilirubin in both human and buffalo erythrocytes whereas in sheep and goat erythrocytes, the pronounced increase was found beyond 2.0 and 2.7 mM MgCl(2) concentrations respectively. Percentage increase in erythrocyte-bound bilirubin was found highest in human erythrocytes followed by buffalo and sheep erythrocytes and minimum in goat erythrocytes. These differences in the binding of bilirubin to different mammalian erythrocytes can be attributed to the differential shielding effect of metal ions which involves the masking of negatively charged phosphate of phospholipids found on the erythrocyte surface.