Poster Presentations Effect of Long-term Ethanol Treatment on the Activity of Superoxide Dismutase and Catalase in the Blood of Cadmium- or Lead-exposed Rats

From many years, it has been well known that the metabolism and toxicity of xenobiotics may be modified by various factors, including intake of bioelements and proteins as well as using stimulants, especially ethanol. Until now interactions of ethanol with drugs have been recognized relatively well. However, interdependences between ethanol and many xenobiotics, including heavy metals such as cadmium (Cd) and lead (Pb) and their consequences for health are not fully understood. The increasing ethanol consumption in various forms (wine, beer, vodka) and presence of Cd and Pb in the occupational or/and environmental conditions prompted us to undertake the studies on interactions between ethanol and these metals. We have noted that shortas well as long-term ethanol administration to rats chronically exposed to Cd or Pb increases accumulation of these metals in organs, especially in the liver and kidney, and modifies their influence on metabolism of some bioelements, including zinc (Zn), copper (Cu) and iron (Fe) [1–3]. Zn and Cu are located in the active centre of superoxide dismutase (SOD) which is an antioxidant enzyme taking part in dismutation of superoxide radicals whereas Fe is located in the active centre of catalase (CAT) which degrades hydrogen peroxide. Ethanoland/or Cdand Pbinduced changes in the metabolism and tissue distribution of Zn, Cu and Fe can contribute to the free radical-related mechanisms underlying of cell, tissue and organ damage by these substances. The aim of the present study was to investigate the influence of long-term ethanol administration on the activity of SOD and CAT in blood of rats exposed to Cd or Pb. Adult male Wistar rats were administered intragastrically ethanol at a dose of 5 g/kg/24 h or/and received an aqueous solution containing 50 mg Cd/ dm# or 500 mg Pb/dm# as the only drinking fluid, for 12 weeks. After the exposure was completed, whole blood was collected and erythrocytes were separated. The activities of SOD (using commercially available kit, RANDOX) and CAT (according to Aebi) were determined in the erythrocytes. The administration of ethanol alone resulted in an increase in SOD activity and a decrease in CAT activity. Exposure to Cd reduced the activities of both enzymes. Pb intoxication increased the activity of CAT but had no influence on SOD activity. In the rats co-exposed to Cd or Pb and ethanol, the activity of SOD was in the range of the group receiving ethanol alone. CAT activity in the rats simultaneously exposed to Cd and ethanol was lower than in the Cd-treated group, whereas in the case of Pb and ethanol co-administration, it was in the range of control values. Concluding, exposure to Cd, Pb and ethanol influences the antioxidative system of erythrocytes.