Effects of cytostatic drugs on the transmembrane potential and surface charge of cultured cells.

The transmembrane potential, the surface charge and the cell count were measured on cells cultured in vitro under the influence of various cytostatic substances. Lower concentrations of the agents induced an increase in membrane polarization. On the other hand membrane depolarization grew with both increasing exposure to cytostatic substances and rising content of the latter in the medium. The influence of higher doses was accompanied by morphological cell damage as well as a decrease in the surface charge of cells after a lengthy incubation time. Immediately after addition of chemotherapeutic substances to the cell cultures a damped oscillation of the TMP was observed. This clearly supports that the TMP is a rapidly reacting and very sensitive indicator for a great number of cell functions and an additional parameter in pretherapeutic sensitivity tests.