Histological examination of the thyroid after experimental administration of Metizol

The investigations were carried out on thyroids of white Wistar rats which were given Metizol for 3 days, 3 and 6 weeks at the dose of 1 mg/kg of b.m. for 24 hrs. The samples were stained with hematoxylin and eosin and by the PAS method. The following changes were observed: 1. Three-day administration of Metizol resulted in the decrease in the quantity of colloid; the secretory epithelium became uniform--i.e. cubic; the quantity of the interfollicular tissue increased. 2. Three-week administration of Metizol resulted in appearing of colloid stained differently than in the control group; secretory epithelium cells were of different height (cubic and cylindrical), a considerate congestion of the gland was visible, the quantity of the interfollicular tissue increased. 3. After 6 weeks of Metizol administration the morphological picture of the thyroid became similar to that of the control group.