百草枯中毒小鼠心肌损伤的病理观察

Ingestion of the herbicide paraquat (PQ) can cause multiple organ injury. Cardiac lesions due to PQ poisoning are also frequent, but these action mechanisms have rarely been studied. The aim of this study was to examine the pathology of PQ-induced myocardial damage. It may provide useful clues for understanding the mechanisms of toxicity. In this study, the experimental mice (n=25) were injected intraperitoneally with 30 mg/kg of PQ to induce myocardial damage. Control mice (n=5) were injected with saline. The pathology of the cardiac muscle, including histopathological examination and changes in ultrastructure were examined at 2, 4, 8, 16, and 24 h after PQ administration.In results, histopathological changes, inflammatory cell infiltration, oedema, nucleus dissolution, intracellular vacuolisation and myocytolysis were observed at different time points following PQ administration. Changes in the ultrastructure of cardiac muscle cells, including damaged mitochondria, ruptured and dissolved myofilaments and vacuolar degeneration in the cytoplasm, were also noticed in the same time. We concluded that the seriously injury changes of cardiac muscle in mice was caused by paraquat. These changes were considered pathologically fundamental for the clinical manifestations of myocardial damage due to PQ poisoning.