Histopathological effects of sodium meta-bisulfite on tissue and thyroid hormones in adult male rats

Sodium meta-bisulfite is an inorganic compound that is used for food storage and may have side-effects on different body organs. Given the importance of thyroid hormones in regulating metabolism and tissues function, this study aimed to investigate the effect of sodium meta-bisulfite on histological structure and thyroid function in adult male rats was performed.
In this experimental study, 70 adult male rats divided as control (no treatment), sham (physiological saline treatment) and 5 experimental groups receiving sodium meta-bisulfite doses at 25, 50, 100, 200 and 400 mg/kg, were used respectively. Prescribed by gavage for 28 days was conducted. Then, after collecting blood samples for measuring the hormones T3, T4 and TSH, their thyroid removed and after preparing tissue sectioning, the follicle were counted and compared and the results using ANOVA and Tukey analyzed, so a significant difference of data at p ≤ /0/05 was considered.
The results showed that sodium meta-bisulfite at doses 100, 200 and 400 mg/kg significantly reduced the amount of T3 and T4 and active follicles numbers and significantly increased the colloid space and inactive follicles at P≤0/001 and so, in doses of 200 and 400 mg/kg, respectively, significantly increase at P≤0/05 and P≤0/001 in TSH hormones levels compared to the control group.
The results showed that sodium meta-bisulfite by reducing the active thyroid number of follicles, leads to decreased thyroid hormones and by removing the negative feedback of these hormones causes increased TSH.