BIOCHEMICAL-CHANGES AND ESSENTIAL METALS CONCENTRATION IN LEAD-INTOXICATED RATS PREEXPOSED TO ETHANOL

The effects of chronic lead exposure on some hematopoietic and hepatic biochemical indices and urine, feces, and tissue essential metal concentration were investigated in rats pre-exposed to different doses of ethanol. Exposure to ethanol (0.5, 1.0, and 2.0 g/kg intraperitoneally, once daily) for 4 weeks produced an inhibition of blood delta-aminolevulinic acid dehydratase (ALAD) activity and a decrease in hepatic glutathione (GSH) concentration. Ethanol ingestion also produced a dose-dependent elevation of hepatic lipid peroxidation. Blood and hepatic calcium and hepatic magnesium contents decreased and urinary Ca and fecal Ca and Mg contents increased significantly following 4-week exposure to ethanol (2 g/kg). Lead administration (10 mg/kg, orally) for 4 weeks in ethanol pre-exposed (2 g/kg) animals produced a more pronounced inhibition of blood ALAD and elevation of urinary delta-aminolevulinic acid (ALA) excretion and hepatic GSH contents. Hepatic GSH contents decreased and hepatic lipid peroxidation increased significantly in rats given lead and pre-exposed to ethanol (2 g/kg). A more pronounced depletion of blood Ca and Mg and hepatic Mg was observed along with significant elevation of urinary Mg and fecal Ca excretion in animals administered lead and pre-exposed to ethanol (2 g/kg). The results suggest that nutritional deficiencies, particularly depletion of body Ca and Mg levels, play an important role in increasing susceptibility to lead intoxication in the rat.