Abstract: Mitochondrial enzymes play important role for cell, but the morphological characteristics, structure and function of enzymes would be changed significantly stressed by heavy metals, and also will be irreversible damaged. This study takes the liver mitochondria of mice as the subject of study under the 50mg/kg, 100mg/kg, 200mg/kg, 300mg/kg, 400mg/kg and 500mg/kg of different concentrations of Pb2+ stress to explore the five mitochondrial enzyme activities. The results showed that SDH, NADH, ATP, GST and GSH-PXG activity decreased as Pb2+ dosage increased. And all reached the bottom after 500mg/kg, which had significant differences compared with controls (P<0.01). Statistical analysis showed that SDH, NADH, ATP, GST and GSH-PX activity had a significant negative correlation with Pb2+ concentration.

Key words: mitochondrial enzyme, Pb2+, toxicological effect, mouse liver