Interaction and Enhancement of the Toxic Effects of Sodium Arsenite and Lead Acetate in Wistar Rats

Continuous exposure of humans to arsenic through long–term ingestion of contaminated drinking water and its attendant health problems has been widely reported. It is also known that arsenic interact with other substances, metals inclusive thereby potentiating its effects or vice versa. In this study, we examined the effects of sodium arsenite (SA) and lead acetate (LA) in wistar rats. Sodium arsenite (2.5mg/kg bd.wt) and lead acetate (14mg/kg bd.wt) were fed to rats by gavage for fourteen consecutive days alone or simultaneously. Control rats were fed with distilled water. Clastogenic effects were observed in the bone marrow cells using the micronucleus assay. In addition, serum activities of gamma glutamyl transferase (γ-GT), alkaline phosphatase (ALP), alanine amino transferase (ALT ) and aspartate amino transferase (AST) were monitored . The findings indicate that SA and LA separately induced the formation of micronucleated polychromatic erythrocytes (mPCEs) in the bone marrow of the rats significantly (P < 0.05) by about 9 and 8 folds respectively. When fed simultaneously, the induction was about 22 folds as compared with the negative control group. SA significantly induced the serum activity of all the enzymes while LA significantly induce the activity of only γ-GT and ALP (P < 0.05). Simultaneous feeding of SA and LA also markedly induced the activity of all the enzymes in the serum. Mild infiltrative haemorrhage was observed in the lungs of rats exposed to the two compounds. This study underscores the enhanced toxic effect of combined or simultaneous exposure to toxic substances.

Keywords
arsenite, lead acetate, gamma glutamyl transferase, alkaline phosphatase, alanine amino transferase and aspartate amino transferase.