Hyperthermia-induced changes in the morphology of CHO-K1 and their refractile inclusions

1. 1.|Chinese hamster ovary cells (CHO-K1) were heated at temperatures of 42°C and above.

2. 2.|Cells were cultured in microcapillaries to eliminate handling stress, and morphological changes were observed by light microscopy.

3. 3.|Increased incidence of membrane blebbing was noted between 1 and 2 h and few cells were viable after 2 h at 43°C.

4. 4.|Morphological changes, including the appearance of potocytotic blebs, were recorded by cinemicroscopy of microcapillary cultures on a heated microscope stage.

5. 5.|Lipid-rich refractile cell inclusions changed shape before blebbing occurred.

6. 6.|Cell retraction and rearrangement of organelles seen at 1 h at 43°C are the reverse of those seen in spreading post-trypsinized cells and suggest a thermal effect on the cytoskeleton.

Author Keywords: CHO-K1; hyperthermia; microcapillaries; cinemicroscopy; blebbing; organelle movement; refractile inclusions; cytoskeleton