Experimental Simulation of the Effects of Essential and Toxic Trace Elements on Thyroid Function

The effects of essential (I, Se, and Zn) and toxic (Pb and Cd) trace elements on the thyroid function were studied experimentally. The protective effects of iodine, zinc, and selenium on thyroid tissue and antithyroid effects of toxic trace elements promoting a decrease in the levels of thyroid hormones (T₃, T₄) and imbalance of pituitary hormones (TSH) were detected. Addition of toxic trace elements to the ration of experimental rats led to their accumulation in the thyroid (0.051 μg/g Pb and 0.190 μg/g Cd). Negative correlations between the levels of toxic and essential trace element accumulation in the organ were detected. Essential trace elements zinc and selenium involved in thyroid hormone metabolism promoted normalization of the thyroid function. A complex of essential trace elements (I, Se, and Zn) was recommended for correction of mineral metabolism under conditions of iodine deficiency and thyroid hypofunction and in exposure to toxic trace elements.