Effect of hyperthyroidism on thyroid hormones levels in prepubertal and pubertal male rats

Abstract

The present study has been designed to investigate wheather silymarin has its own antioxidant activity and/or it act through induction of the endogenous antioxidants. The present study has been conducted in the animal house of the college of veterinary medicine, AL-Qadisiya University during the period extended from October, 2021 to April, 2022. Thirty-two premature (aged 40 days) and thirty-two mature (aged 70 days) male rats. Divided to 4 groups each 16 rats 2 subgroups 10 and 20 days as following, Pre-pubertal control group (C-pre): 16 premature male rats (aged 40 days) will be orally administered for 20 days with distilled water. Pre-pubertal hyperthyroid group (H-pre): 16 premature male rats (aged 40 days) will be orally administered for 20 days with thyroxine (T4) in drinking water (0.002% w/v) beside intragastric gavage of 200 T4 μg/kg body weight. Post-pubertal control group (C-pre): 16 mature male rats (aged 70 days) will be orally administered for 20 days with distilled water. Premature hyperthyroid group (H-pre): 16 mature male rats (aged 70 days) will be orally administered for 20 days with thyroxine (T4) in drinking water (0.002% w/v) beside intragastric gavage of 200 T4 μg/kg body weight. At the end of each treated and control subgroup period, males were anaesthesized (by injection of 0.3ml ketamine + 0.1 ml of xylazine/ kg b.w. ip), dissected and blood samples were obtained from abdominal vein in non-heparinized tubes. Blood serum samples were separated for assessment of T3, T4 and TSH concentrations. At the end of each experimental period, a significant changes of serum T3, T4 and TSH concentrations.