FIGURE 1.

Hyperosmotic conditions results in a rapid and sustained decrease in cell volume in S49 (Neo) cells. A, S49 (Neo) cells treated with 250 or 500 mOsm mannitol were examined for initial changes in cell size (EV) using a Cell Lab Quanta flow cytometer. An immediate decrease in MCV was observed under both conditions. B, S49 (Neo) cells treated as above were examined over time for changes in cell size. Both conditions resulted in shrunken cells that remained shrunken throughout the time examined, suggesting the absence of an inherent RVI. In contrast, S49 (Neo) cells under a hypoosmotic condition initial showed a rapid increase in cell size that was compensated through an RVD response resulting in a near normal cell volume. Data represent the mean (± S.E.) of three independent experiments. *, p < 0.001 versus control.