Daily intake of lead in Wistar rats at different ages: Biochemical, genotoxic and physiological effects

• The effects of daily intake of feed containing lead were evaluated in 45 (Pb45) and 90 (Pb90)-day-old Wistar female rats.
• Compared to the respective control, Pb45 group consumed more feed and showed greater weight gain.
• Only Pb90 showed hematological changes, with lower hemoglobin levels.
• Pb45 and Pb90 groups showed higher blood glucose, but plasma insulin was higher in the Pb45 but lower in the Pb90.
• Pb45 and Pb90 showed increased lipid peroxidation in the liver and DNA damage in the lymphocytes.

The effects of the daily intake of feed containing lead (2.0 mg Pb kg−1) were evaluated in 45 (Pb45) and 90 (Pb90)-day-old Wistar female rats. Compared to the respective control groups, Pb45 rats consumed more feed and showed greater weight gain, but these parameters returned to control values in Pb90 rats. Higher blood glucose levels were observed in both Pb groups, whereas plasma insulin concentrations were higher in Pb45 but lower in the Pb90 group. Liver glycogen content was lower only in the Pb90 rats. There were no changes in plasma cortisol and acetylcholinesterase activity in the brain. Hematological alterations were observed only in Pb90 rats, which showed lower hemoglobin levels. In the liver, Pb45 rats showed decreased catalase and glutathione peroxidase activities and increased glutathione reductase activity, but in the Pb90 group, glutathione levels were higher. Increased hepatic lipid peroxidation and DNA damage in the lymphocytes were observed in both Pb groups. These results indicate that the daily intake of Pb for different periods results in metabolic changes and in the establishment of oxidative and genotoxic damage in female rats.