The influence of inorganic silicon (Si) on pituitary-thyroid axis.

The influence of silicon-treatment on the levels of TSH and thyroid hormones was studied in rats. Concentrations of thyrotropin (TSH), triiodothyronine (T3), and thyroxine (T4) were estimated in sera of rats receiving per os a soluble silicon compound--sodium metasilicate nonahydrate (Na2SiO3.9H2O), dissolved in the animals' drinking water. An increase in the TSH level in the tested group was observed, without statistically significant differences in T3 and T4 concentrations between the two groups of animals. The results provide evidence for the influence of silicon on the endocrine balance. They could also prove that this chemical element is capable of modifying the rate of some hormones' synthesis.