Abstract :
This study was designed to investigate the mechanism of zinc, copper and chromium toxicity after exposure for two different durations (4 weeks and 8 weeks). Ninety six adult male albino rats were divided into 8 groups 12 rats each. G1 (C1): served as healthy control; G2 (Zn1), G3 (Cu1) and G4 (Cr1) were received 500, 200 or 8 mg/day of zinc, copper and chromium, respectively for 4 weeks. While G5 (C2) served as healthy control; G6 (Zn2), G7 (Cu2) and G8 (Cr2) were received the same doses of metals for 8 weeks. The results of this study revealed that exposure to the three metals have detrimental effects in a time dependent manner. A significant reduction (P≤0.05) in liver and kidney functions; also hemotoxic effect was confirmed by reduction in Hb concentration and deteriorations in blood cells count and shapes; in addition, results showed a significant increase in serum MDA, NO and OSI and a significant reduction (P≤0.05) in TAC and GSH levels and SOD activity; marked elevations in TNF-α, IL-6, IL-1β, CRP, MPO and EMAP-II. Moreover, tested metals caused disturbances in immune system, negative effect on brain neurotransmitters, sever elevation in DNA fragmentation percentage and PCG level in spleen and brain tissues and serum LDH activity, cytosolic and mitochondrial dysfunction in spleen and brain tissues appeared as significant elevation in IDH activity and CCO. The microscopic examination for spleen and brain confirmed damage to these tissues.
