THE EFFECT OF TOTAL SAPONINS FROM PANAX-GINSENG MEYER,C.A. ON THE INTRACELLULAR SIGNALING SYSTEM IN EHRLICH ASCITES TUMOR-CELLS

The mechanisms of action of total saponins from Panax Ginseng C.A.Meye r on the elements of intracellular signalling system in Ehrlich ascite s tumor cells were studied. The action of total saponins was compared with the effect of ATP, a classical activator of these cells. Saponins at concentrations of 10(-6)-10(-3)% increased [Ca2+]i, mobilized Ca2 ions from the endoplasmic reticulum (ER) and activated the influx of Ca2+ to cells. Like ATP, saponins activated the Na+/H+ exchange and Ca 2+-dependent K+ channels. Of an. the parameters, only the activation o f Ca2+ influx in cell is directly affected by saponins. The changes in other parameters are connected with nonspecific activation of purinor eceptors. The analysis of the kinetic data suggests that, as distinct from ATP-dependent activation of purinoreceptor, saponins first activa te the Ca2+ influx to cells and only then induce the mobilization of C a2+ from ER.