Morphology, Histopathology and Hematology as Biomarkers of Cadmium Toxicity in Field Rats

Background: Cadmium is known as a unique heavy metal compared to others, due to its long half-life, low discharge from the body, toxicity at low concentrations and accumulation in tissues. Methods: The effects of chronic and acute Cadmium (Cd) exposure were investigated on the morphology and histopathology of 24 field rats (Millardia meltada). The rats were divided into two groups of 12 each, then sub-divided into: one control and two treatment sub-groups with Cd in the feed or water. The treatment subgroups received either 15mg/kg (low) or 30mg/kg (high) Cd concentration in the feed.  Results: Hemorrhagic spots and fibrosis were observed in the liver of Cd treated rats compared to the controls. Also, necrosis, dilation, and calcinosis occurred in the renal tubules of the treatment groups compared to the controls. The levels of hemoglobin, red and white blood cells, hematocrit, and mean corpuscular hemoglobin were reduced, while mean corpuscular volume and hemoglobin concentrations were increased. Conclusion: This study reports the morphological, pathological and hematological abnormalities in the blood, liver and kidneys of rats due to Cd toxicity, which may be considered as the biomarkers of cadmium toxicity in other experimental mammals.