Protective effect of zinc on related parameters to bone metabolism in common carp fish (Cyprinus carpio L.) intoxified with cadmium.

The short term effects of waterborne cadmium (Cd(+2)) on the levels of serum parameters related to bone metabolism including calcium (Ca), inorganic phosphorus (P(i)) and alkaline phosphatase (ALP) in common carp fish (Cyprinus carpio L.) were studied. Fish were treated with varying concentrations of Cd(+2) (0.22, 1.1 and 2.2 mg l(-1)) daily for 14 days. The results obtained show that serum P(i) and ALP concentrations were elevated by increasing Cd(+2) concentration in water containing fish whereas serum Ca level was decreased. At the same time, the protective role of waterborne zinc (Zn(+2), 1 mg l(-1)) on the same parameters was also investigated. Results showing that daily treatment of fish with Zn(+2), increased the concentrations of Ca and ALP in serum by 2.07 and 1.86 fold and decreased serum P(i) level by 57.7% in comparison with Cd(+2) treatment. The combination of Cd(+2) and Zn(+2) on the same parameters was studied next. There was a significant (P < 0.05) elevation in serum Ca and ALP levels in comparison with Cd(+2) treatment. Decreasing in serum P(i) level was not significant in comparison with Cd(+2) treatments. The protective effect of Zn(+2) on Cd(+2) disturbances in serum parameters related to bone metabolism in this manuscript has been also discussed.