Effect of peroxynitrite on production of superoxide anion radicals and calcium homeostasis in cells of astroglial origin

Abstract

We studied the effect of a donor of peroxynitrite, SIN-1, on the morphological characteristics of interweaved rat C6 glioma cells, on menadione-induced production of superoxide anion radicals, and on the concentration of Ca2+ in these cells. In concentrations of 1.25·10−4 to 2.5·10−7 M, SIN-1 demonstrated cytotoxic and antimitogenic effects. This donor of peroxynitrite caused abnormal modifications of the size of C6 cells and the structure of cellular organelles, intensified in a dose-dependent manner the release of Ca2+ from cellular stores into the cytoplasm, and suppressed menadione-induced production of superoxide anion radicals. Therefore, it should be believed that peroxynitrite exerts a modifying effect on the processes of mitotic division and induces apoptosis; it is also involved in the processes of intracellular signalling providing an increase in the concentration of cytosolic Ca2+ and a decrease in the redox activity of cells.