摘要：Background and Objective: Lead (Pb) has a variety of uses, namely in making bullets, pipes, wires, sinks, containers, leaded gasoline, paints, battery and radiators. Lead emissions cause environmental contamination which affects nervous, renal and cardiovascular systems. Lead is known to cause biochemical alterations in tissues. The present study evaluates the acute effects of lead at sub-lethal concentrations in zebrafish. Materials and Methods: A total 72 zebrafish were divided into four groups viz. control and exposed groups which were given 0.5, 1.0 and 2.0 mL L1 (ppm) of lead CRM for 24 h. Levels of malionaldehyde, glutathione and antioxidant enzyme activities were determined in liver, kidney and brain. Statistical significance was determined using one-way ANOVA where p < 0.05 was considered as significant. Results: Acute exposure of zebrafish to lead caused increased lipid peroxidation and elevated activity of glutathione peroxidase in a concentration dependent manner. However, no change in glutathione content was observed at 0.5 mL L1 concentration while it was elevated at 1 mL L1. There was alteration in the activity of other enzymes in a concentration dependent manner. Increased concentration of lead affected the brain tissue more as compared to liver and kidney. Conclusion: Lead exposure induces oxidative stress and a decline in enzyme activity presumably causes lipid peroxidation due to increase in the levels of reactive oxygen species . The biochemical mechanisms mediating low-level toxicity are not clearly understood but in several biological systems lead (Pb) alters cellular processes. Studies suggest that no threshold levels for lead have been prescribed which causes adverse effects. Safe disposals of domestic sewage and industrial effluents as well as enforcement of laws to protect our environment are therefore advocated.
