Acute and chronic pathological effects with biochemical alteration of thyroid gland induced by NaF in Wistar rats

Thirty Wistar albino rats of both sex, 1-1.25 months old (average body weight 250 – 300gm) were used. Animals were randomly divided into three groups. 1st group (acute group) n=10 given 0.5 ml. contain 500 mg/kg/body weight NaF, as single toxic dose via stomach tube. 2nd group (chronic group) n=10 given 0.5 ml. contain 150 mg/kg/body weight NaF via stomach tube daily for 60 days. 3rd group (control group) n=10 given 0.5 ml. physiological saline via a stomach tube. Clinical signs were reported during the course of the study, and then sacrificed after 3 and 7 days in 1st group, and 30 and 60 days in the 2nd group, then post-mortem examination was done, and any gross lesions were reported. Blood collected was done for biochemical examination (T3, T4, and TSH.) using special biochemical kits. Pieces of thyroid were taken, fixed in 10% formalin for 72 hours, and then all the specimens were processed and the histopathological changes were observed under a light microscope. The pathological results showed hemorrhage appear in the capsular region of the thyroid gland with vacuolation in the cytoplasm of a cell of a colloid with neutrophils infiltration in the lumen, as well as edema with fume cytoplasm and marked vacuolation of the cytoplasm of a colloid cell, also granulomatous lesion seated in gland parenchyma. That causes alteration of biochemical test T3, T4, and TSH in acute and chronic toxic doses