Effects of saponins of Panax notoginseng on sodium-potassium-adenosine triphosphatase and calcium-magnesium-adenosine triphosphatase.

Rat brain synaptosomal Na(+)-K(+)-ATPase was activated by Panax notoginseng (PNS, 0.1-1.0 mg.ml-1), fraction Rb1 (25-200 micrograms.ml-1), and fraction Rg1 (50-200 micrograms.ml-1). Activating rates were respectively 84-227%, 12-48%, and 12-22%. Results implied that Rb1 and Rg1 were not the major components of PNS, which were responsible for the activating effects. Ca(2+)-Mg(2+)-ATPase was inhibited by PNS (0.1-1.0 mg.ml-1) and Rb1 (100-200 micrograms.ml-1), but not by Rg1. It was proposed that PNS activated Na(+)-K(+)-ATPase, leading to a reduced Na+/Ca2+ exchange, a lowered intracellular Ca2+ level, and heart contractility.