Development of brain free radical scavenging system and lipid peroxidation under the influence of gestational and lactational cadmium exposure.

1. Rat pups were exposed to cadmium (Cd) gestationally and lactationally through mothers receiving 20 ppm Cd in drinking water, ad libitum, from zero day of pregnancy. 2. The sequential measurement of brain lipid peroxidation showed an increase in thiobarbituric acid reactive substances at 1 (73%), 7 (30%), 14 (22%) and 21 (354%) days of age compared to respective controls. 3. A marked variation in reduced glutathione levels was observed at different postnatal ages of both control and Cd-treated groups. The levels of brain total sulphydryls were increased significantly in experimental animals at 1 (30%) and 7 (12%) days of age. 4. Cd exposure increased the activities of superoxide dismutase and glutathione peroxidase by 45% and 104%, respectively, at day one. However, the continuous exposure inhibited them at 7, 14 and 21 postnatal days. 5. Cadmium treatment elevated the levels of brain catalase and glutathione reductase at all the studied ages with a maximum alteration of 66% and 50%, respectively, at 21 days of age. 6. The data indicate that the exposure of pregnant mothers to low doses of Cd produced changes in the brain antioxidant defence mechanisms at critical periods of development which may have serious implications in later life.