EFFECTS OF EXTREME HYPOXIA ON THE GROWTH AND VIABILITY OF EMT6-SF MOUSE-TUMOR CELLS-INVITRO

  • 1 January 1983
    • journal article
    • research article
    • Vol. 43  (8) , 3521-3527
Abstract
A model system was characterized in which to study hypoxic cell biology in vitro as a function of time under extremely hypoxic conditions. EMT6/SF cells that were maintained at 37.degree. under hypoxic conditions showed no increase in cell number for up to 70 h. The mitotic index of hypoxic cultures < 0.1%, compared to 2.3-3.0% in aerated cultures. The plating efficiency of hypoxic cells decreased with time to 20-30% of control values by 70 h. Aerated cultures consumed glucose more rapidly than did hypoxic ones, due to increasing cell number in air. But, on a per cell basis, hypoxic and aerated cells consumed glucose at equal rates .simeq. 1.2 .times. 10-4 .mu.g/cell per h. Virtually 100% of the glucose consumed was converted into lactic acid in both aerated and hypoxic cultures. The labeling index and rate of incorporation of [3H]thymidine decreased exponentially with time in hypoxia. However, the percentage of cells with S-phase DNA content remained nearly constant for up to 72 h. The rate of protein synthesis was suppressed in hypoxic cultures to between 20 and 50% of control (aerated) rates. When cultures were reaerated following 45 h of hypoxia, .simeq. 12 h was required for resumption of DNA synthesis and cell division. The application of this system to further study of hypoxic cell biology is discussed.