Histopathological Changes in Rat Hypothalamus After Propylthiouracil Induced Hypothyroidism and The Protective Role of Folic Acid

Background: Hypothyroidism means that the thyroid gland can't make enough thyroid hormone to keep the body running normally. We studied the histopathological and immunohistochemical changes in the hypothalamus of hypothyroid rat at the post-pubertal stage, in addition to the ameliorating role of folic acid.Material and Method: Twenty male albino rats were equally divided into four groups; the first and second groups were the control and folic acid groups respectively while the third group was the hypothyroid group in which rats received propylthiouracil (PTU) in drinking water for 6 weeks to induce hypothyroidism. The fourth group was hypothyroid rats treated with folic acid for four weeks and dissected after 6 weeks. In order to ensure the hypothyroid state, the level of serum T3 and TSH through the dose period were regularly determined.Results: The levels of TSH in hypothyroid rats were significantly higher while the levels of T3 were significantly lower in hypothyroid rats when compared to control rats group. A variety of changes were observed in the hypothalamus of hypothyroid compared with control rats. Microscopically, the hypothalamus of hypothyroid rats showed diffuse vacuolar degeneration and damages neurons especially in both SCN and SON.Conclusion: Treatment of hypothyroidism with folic acid depressed the histopathological alternation.