Differential influences of various arsenic compounds on antioxidant defense system in liver and kidney of rats

• iAs(III) and iAs(V) have similar potency to inhibit/induce antioxidant defence system.
• Liver is more sensitive to acute As(III)- and As(V)-induced oxidative stress.
• Both As(III) and As(V) inhibit thioredoxin reductase activity “in vivo”.
• Inhibition of hepatic GPx and TrxR could reflect reduced selenoproteins synthesis.

In this study, oxidative stress-related parameters and As retention were examined in liver and kidneys of male Wistar rats exposed to arsenic trioxide, sodium arsenite (iAsIII), sodium arsenate (iAsV), and dimethylarsinic acid (DMAsV) at a single ip dose of 3.8 mg As/kg bw, at 24 h post-exposure. In liver, lipid peroxidation increased in iAsIII-exposed rats, glutathione peroxidase activity decreased in inorganic arsenic (iAs)-exposed rats, and catalase and thioredoxin reductase activities decreased significantly in all As-exposed groups. Both As(III) and As(V) exposure elevated GSH level with no effect on glutathione reductase activity. In kidneys, catalase activity decreased significantly in iAs-exposed, rats; GSH level, glutathione reductase and thioredoxin reductase activity decreased in DMAsV-treated, rats. The tissue As retention was higher in kidneys compared to liver and was also higher in As(III)-exposed compared to As(V)-exposed rats. The results demonstrate similar potency of inorganic As(III) and As(V) compounds to inhibit/induce antioxidant defense system, with liver being more vulnerable to acute As(III)- and As(V)-induced oxidative stress.