engleski

Effects of long-term lead exposure on antioxidant enzyme defense system in organs of brown hare (Lepus europaeus Pallas) as a bioindicator of environmental pollution in Croatia

In Croatia, Podravina is a well-known lead- polluted region due to the intensive exploitation of natural gas, a highly developed agricultural industry and a traffic hub with several heavily traveled roads. It represents a natural environment with a great variety of wildlife, especially hares (Lepus europaeus Pal-las), which may serve as an indicator for environmental quality assessment. This study was conducted to estimate the bioaccumulation of lead in hare liver, kidney, muscle and brain during long-term exposure and its impact on the oxidative status of the organism and to investigate a possible lead exchange ionic mechanism in the brain. In the organs of two hare groups (experimental from polluted area and control from the island of Krk), Ca, Fe, Mg, Na, lead concentrations, and antioxidant enzyme defense system were analyzed. The accumulation of lead was highest in brain (3.7-fold higher compared to the control group) and lowest in liver (1.6-fold higher compared to the control group). Kendall-Tau and multiple regression analysis showed that the increased lead content caused a stronger exchange of Ca and Na ions in the brain. We proposed that lead either mobilizes intracellular cation stores or causes competitive dis-placement of Ca from the binding site in intoxicated cells. A linear predictive model for cell intoxication by lead was proposed, where GPx and SOD were predominantly influenced by long-term lead exposure. The presented results showed that long-term lead exposure in hares negatively affected their oxidative status and caused the strongest toxicity in the brain and muscles, making their survival and/or population vulnerable.

biomonitoring, hare, lead, minerals, oxidative stress enzymes

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