Pathological anatomy of thyrotoxic liver

Abstract

The work was performed on experimental material. An experimental model of thyrotoxicosis in laboratory animals, white male rats, was obtained by daily administration оf l-thyroxine at a dose of 1.6 mg per 1 kg of body weight. The duration of the experiment was 45 days. 67 mature rats weighing 250–300 g were selected for the experiment. Rats were removed from the experiment after 7, 14, 21, 28, 35 and 45 days. As a control, we used 22 rats that were not injected with L-thyroxine. The level of thyroid hormones in the blood of rats was determined by enzyme immunoassay. A macroscopic study was performed and the size and mass of the rat liver were determined. For histological examination, pieces of liver tissue were taken, and they were fixed in 10 % buffered formalin for 10 days. Histological preparations were prepared by the standard method, using histological, histochemical and immunohistochemical studies. The results of the study showed that in experimental thyrotoxicosis, the level of thyroid hormones increases: T3 (triiodothyronine) equals 21.37 ± 0.03 mmol/l, 4.75 ± 0.02 mmol/l in the control; T4 (thyroxine) equals 2.55 ± 0.03 mmol/l, 1.80 ± 0.03 mmol/l in the control. Macroscopic examination revealed a 2-fold increase in the size and weight of the liver. Histological examination revealed widespread interstitial edema of the liver stroma, dystrophic and destructive changes, necrosis of hepatocytes, formation of cavities, thinning and atrophy of the liver beams, lymphocytic infiltration. The immunohistochemical study shows a decrease in Ki-67 expression level to 1.8 % compared to the control (5.0 %), which indicates a decrease in reparative processes in the liver.