Abstract:
BACKGROUND/AIMS : Heavy metal pollution is increasing in the environment, contaminating
water, food and air supplies. This can be linked to many anthropogenic activities. Heavy metals
are absorbed through the skin, inhalation and/or orally. Irrespective of the manner of heavy
metal entry in the body, the blood circulatory system is potentially the first to be affected
following exposure and adverse effects on blood coagulation can lead to associated thrombotic
disease. Although the plasma levels and the effects of cadmium (Cd) and chromium (Cr) on
erythrocytes and lymphocytes have been described, the environmental exposure to heavy
metals are not limited to a single metal and often involves metal mixtures, with each metal
having different rates of absorption, different cellular, tissue, and organ targets. Therefore
the aim of this study is to investigate the effects of the heavy metals Cd and Cr alone and
whether Cr synergistically increases the effect of Cd on physiological important processes
such as blood coagulation. METHODS : Human blood was exposed to the heavy metals ex vivo,
and thereafter morphological analysis was performed with scanning electron- and confocal
laser scanning microscopy (CLSM) in conjunction with thromboelastography®. RESULTS : The
erythrocytes, platelets and fibrin networks presented with ultrastructural changes, including
varied erythrocytes morphologies, activated platelets and significantly thicker fibrin fibres in
the metal-exposed groups. CLSM analysis revealed the presence of phosphatidylserine on the
outer surface of the membranes of the spherocytic erythrocytes exposed to Cd and Cr alone
and in combination. The viscoelastic analysis revealed only a trend that indicates that clots
that will form after heavy metal exposure, will likely be fragile and unstable especially for Cd
and Cr in combination. CONCLUSION : This study identified the blood as an important target
system of Cd and Cr toxicity.
