Anti-Thyroid Effect of High Aluminum Intake in Rats

Patients with chronic renal failure have abnormal thyroid function and higher levels of serum aluminum. In recent years, the toxicity of Al in human and animals has been a matter of concern_ In this study the effect of high aluminum intake in the diet has been investigated in rats.
Materials and Methods: Aluminum (1620 mglkg of the diet as aluminum chloride) was added to the diet of Wistar rats for 40 days. At the end of this period serum aluminum, T4 and TSH concentrations were measured. Aluminum was determined by atomic absorption spectrometry and the hormones were assayed using commercially available kits.
Results: Serum aluminum concentration of the test rats (6.3±.1 pgIL) was not significantly different from controls (6.6±.4 pgIL). Serum T3 concentration in animals consuming a diet with high aluminum content (138±8 ngldL) was not significantly different from the control animals (146±7 ngldL). Serum T3, T4 concentration of the test animals (3.0±0.3 pgldL) was significantly lower than control animals (4.7±0.5 pgldL, p<0.05). Thyrotropin concentrations were not significantly different.
Conclusion: The results of this study indicate that high aluminum intake in rats can disturb thyroid function and possible adverse effect(s) of the element need to be considered and fully investigated in subjects in close contact with high amounts.