ABSTRACT
In this study, the effects of the metal ion constituents of Ethiope River which include Fe, Cu, Hg, Cr, Cd, Mn and Pb on selected biochemical parameters and histopathology of rat liver and kidney were investigated.
The study covered a period of 3 months (90 days), in which Fe, Cu, Hg, Cr, Cd, Mn and Pb were administered singly and in combination (Fe and Hg) as well as a combination of all metals listed above, via drinking water. The animals, rats, were divided into twelve groups of five rats each. Group A rats served as control and were not exposed to the metals, group B rats were exposed to boiled Ethiope River water, group C rats were exposed to unboiled Ethiope River water, Group D rats were exposed to combination of all metals Fe (0.72 mg/l), Cu (0.001 mg/l), Hg (0.001 mg/l), Cr (0.001 mg/l), Cd (0.001 mg/l), Mn (0.001 mg/l), Pb (0.001 mg/l), group E rats were exposed to Fe (0.72 mg/l), group F rats were exposed to Cu (0.001 mg/l), group G rats were exposed to a combination of Fe (0.72 mg/l) + Hg (0.001 mg/l), Group H rats were exposed to Hg (0.001 mg/l), group I rats were exposed to Cr (0.001 mg/l), group J rats were exposed to Cd (0.001 mg/l), group K rats were exposed to Mn (0.001 mg/l) and group L rats were exposed to Pb (0.001 mg/l).
At the end of 90 days treatment with tainted water, rats exposed to Hg, Cd and Pb singly had significantly increased (p ≤ 0.05) sodium, potassium, urea, creatinine, chloride, total protein, direct bilirubin, and total bilirubin and cholesterol levels when compared to the control group. Also there were significant increases (p ≤ 0.05) in alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT) and lactate dehydrogenase (LDH) activities in rats exposed to Hg, Cd, and Pb singly compared to the control group. There were no significant increases (p > 0.05) in sodium, potassium, urea, creatinine, chloride, total protein, direct bilirubin, total bilirubin and cholesterol levels, alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT) and lactate dehydrogenase (LDH) activities in rats exposed to Ethiope River water (boiled and unboiled) compared to the control group. These results showed that when metals investigated in this study were administered singly or exist alone in solution their toxic effects increases , but when they exist in combination (as in the river water) their toxicity is reduced possibly due to antagonistic effects of the individual metals on each other.
