Cytopathological lesions of H9C2 cells heat-stressed in vitro.

H&E staining, scale bar = 10 µm. (a) No obvious pathological changes were observed in control H9C2 cells. In heat-stressed H9C2 cells, the following were observed at the indicated time points: (b) 20 min, acute degeneration characterized by enlarged cell size (▴); (c) 40 min, light and clear pink granulation (▾) in the cytoplasm and karyopyknosis (→) was observed; (d) 60 min, cloudy cytoplasm (▴). (e) 80 min, enlarged cell size (▴) and intracellular granules (▾); (f) 100 min, acute granular degeneration characterized by numerous pink granules (▾) and enlarged cell size (▴).