Effect of Hyperthyroidism Induction on Zinc and Copper Levels of Seminal Plasma in Rats

Thyroid hormones can be effective in regulating the metabolism and tissue growth. Clinical literature demonstrates that most patients with disorders of thyroid hormone experience some kind of sexual dysfunction. It seems that hyperthyroidism can cause fertility impairment by altering the levels of trace elements in the semen, which was investigated in this study. Therefore, in this study we investigate the semen levels of zinc and copper during hyperthyroidism induction by levothyroxine in rats. Experimental groups divided into 3 groups: Control group, two hyperthyroid groups which treated by levothyroxine with low dose (4 mg per liter) and high dose (12 mg per liter) for 35 days (groups of 1 to 3). At the end of the experiment, the levels of T3 and T4 were measured by Radioimmunoassay. Also, the levels of copper and zinc in the seminal plasma were measured by Inductively coupled plasma-optical emission spectroscopy and compared to control group. The levels of T3 and T4 were increased significantly in hyperthyroidism groups that received low and high doses of levothyroxine compared to control group (p < 0.05). The level of copper and zinc in the seminal plasma were increased significantly in hyperthyroid group (p < 0.05), (p < 0.001) compared to control group. The results of this study suggest that hyperthyroidism may lead to infertility by altering the levels of trace elements in semen, which can negatively impact sperm quality and function.