Glutathione peroxidase and catalase in liver, kidney, testis and brain regions of rats following cadmium exposure and subsequent withdrawal.

Intraperitoneal administration of 0.4 mg/kg Cadmium (Cd) daily for 45 days was found to inhibit the activities of glutathione peroxidase and catalase in liver, kidney, testis and various brain regions at different time intervals. The magnitude of inhibition was increased with the period of exposure. Cd produced significant inhibition of glutathione peroxidase at 15 days in liver, kidney and cerebellum only; however, the enzyme activity was found to be decreased in all the tissues, except corpus striatum, at 30 and 45 days of exposure. Hippocampal glutathione peroxidase remained unaltered throughout the experiment. Catalase was found to be inhibited in all the tissues at different time intervals. The withdrawal of Cd treatment for 15 days after 45 days of exposure did not show significant recovery in the activity of both enzymes of different organs, except kidney and testis where partial and full recoveries respectively were observed. Since these two enzymes constitute an important part of cellular defence mechanism against oxidation, their widespread persistent inhibition may be of great significance in view of the recent reports showing the possible involvement of oxidative stress in the mechanism of Cd toxicity.