Protective action of polyelectrolytes on endothelium.

These results show that heparin and dextran sulfate protect endothelial cells from oxygen-free radicals. Heparan sulfate and dermatan sulfate showed mild protection when measuring cell viability but none when examining the presence of LDH in media. These GAGs are obviously not as effective as heparin and dextran sulfate in protecting endothelial cells from free radical injury. It is possible, however, that other preparations of heparan sulfate and dermatan sulfate may be more effective. In cells that were pretreated with heparin for 24 hours, the protective action occurred immediately after the addition of X/XO. We can conclude that changes observed in cell viability with heparin treatment were not due to stimulation of cell growth, since this occurred too rapidly. As well, we did not observe a significant difference in cell number in cultures treated with polyelectrolytes. These results show that the anionic polyelectrolytes, in particular heparin and dextran sulfate, may be important for the treatment of ischemic episodes and inflammatory associated conditions. As well, this provides support for the argument that heparin and similar drugs are important for the prevention and treatment of atheroma. It is also possible that the presence of heparin in the mast cell may be to prevent surrounding cells from inflammatory injury.