Effect of aluminium supplementation on thyroid function in rat

Patients with chronic renal failure have abnormal thyroid function and higher serum aluminum (Al). In recent years the toxicity of Al in human and animals has been a matter of concern. In this study the effect of high Al intake in the diet has been investigated in rats. Aluminum (1620mg/kg of the diet as aluminum chloride) was added to the diet of Wistar rats for 40 days. At the end of this period serum Al, T4 and TSH concentrations were measured. Al was determined by atomic absorption spectrometry and the hormones were assayed using commercially available kits. Serum Al concentration of the test rats (6.3±.1 μg/l) was not significantly different from controls (6.6±.4 μg/l). Serum T3 concentration in animals consuming diet with high Al content (138±8 ng/dl) was significantly lower compared to the control animals (146±7 ng/dl). Serum T4 concentration of the test animals (3.0±0.3 μg /dl) was also significantly lowers than control animals (4.7±0.5 μg/dl). Thyrotropin concentrations were not significantly different. The results of this study indicate that high Al intake in rats can disturb thyroid function and the possible adverse effect(s) of the element should be considered and fully investigated in subjects in close contact with high amounts.