LAUSR

ABSTRACT Objectives: Arsenic is a ubiquitous element that is widely distributed in the environment to which man and animals are exposed. Cardiovascular disease is one of the aftermaths of chronic arsenic exposure-related morbidity and mortality. This study sought to investigate the possibility of reversal from arsenic-induced cardio-renal toxicity following exposure and subsequent withdrawal. The study also seeks to understand the mechanism of action of this reversal. Methods: Rats were orally exposed to sodium arsenite at 10, 20 and 40 mg/kg daily for 4 weeks followed by 4 weeks of withdrawal. Results: Exposure to arsenic caused a significant increase in malondialdehyde, H2O2 generation but decrease total thiol and reduced glutathione levels in both cardiac and renal tissues. Furthermore, increases in superoxide dismutase, glutathione-S-transferase and catalase with significant increases in glutathione peroxidase activities were observed in the cardiac tissues. On the contrary, a significant reduction in the renal antioxidant enzyme activity was recorded following exposure. Also, antioxidant defense system did not return to apparent values after arsenic withdrawal. Immunohistochemistry revealed a reduction in the expression of the pro-survival protein–protein kinase B (Akt/PKB) following exposure to arsenic and this was not reversed by withdrawal Discussion: Exposure to arsenic caused cardio-renal toxicity via induction of oxidative stress and down-regulation of Akt/PKB expressions.