Histomorphological changes in various rat tissues following chronic exposure to copper-zinc-pyrite ore

Aim. To assess the histomorphological state of lung, gastrointestinal and kidney tissues following exposure to ­copper-zinc-pyrite ore in the long-term model experiment. Methods. The study was performed on 60 outbred albino male rats, aged 3–4 months, weighting 200±30 g. The ­toxic effect of heavy metal salts of copper-zinc-pyrite ore on the animal's body was analyzed by the model of dosed oral injection of water with ore in a dose 600 mg/kg body weight for 120 days. Pieces of the stomach, small and colon, liver, lungs and kidneys were taken from control and experimental rats for histomorphological study on the 30th, 60th, 90th and 120th day of the experiment. Results. The structural disorders of the stomach lining were observed on the 30th day of the experiment: desquamated and dilapidated epithelial cells appeared in the preparations. On the 120th day, along with signs of epithe­lial desquamation and diffuse lymphocytic infiltration, the preparations contained large lymphoid follicles that occupy the full thickness of the gastric mucosa. The epithelial layer of the small intestine mucosa was disrupted on the 60th day. At day 120 diffuse infiltration and necrotic changes in the lining of the small intestine were recorded. Lymphomacrophagia infiltrations were observed during portal triad and inside the liver wedges of experimental ani­mals on the 30th day of the experiment. By the end of the experiment, toxic hepatocyte dystrophy developed. On the 60th day, signs of bronchopneumonia appeared in the lung tissue. After 3 months, tubulopathy and tubulointerstitial nephritis were observed in the experimental animals. Conclusion. Prolonged administration of ore has led to pronounced inflammation and degenerative changes in the gastrointestinal tract, liver, kidney and lung tissues, accompanied by lymphocytic tissue reaction.