IMPORTANCE OF VARIOUS TYPES OF METABOLIC INHIBITION FOR CELL-DAMAGE CAUSED BY DIRECT MEMBRANE DAMAGE

Cell damage is caused by energy depletion or by direct membrane damage , or a combination when a direct membrane damage affects energy deplet ed cells. In this report it was investigated whether the extent of dir ect membrane damage induced by lysophosphatidyl choline (LPC) or phosp holipase C (PhC) on quiescent fibroblasts depended on the metabolic st ate of the cells. When glycolysis was inhibited cell damage was always extensively increased, whereas cell damage was also increased to a mi nor degree when exposed to PhC during sole inhibition of oxidative pho sphorylation. Acceleration of glycolysis in cells with a low rate of g lycolysis resulted in a dramatic improvement of the membrane susceptib ility within a few minutes. Thus, susceptibility of the cell membrane to direct membrane damage depends on the metabolic state. The results also emphasize previous findings that glycolysis has a special role in maintaining membrane function and integrity.