Effects of Saponins from Stems and Leaves of Panax quinquefolium L.on Contraction of Rabbit Aortic Strips The Effects of PQS and Its Monomer Ginsenoside on Heart Protective Effects of PQS on Oxidative Damage of Cultured Rat Cardiac Cells Anti-hypoxia and Anti-glucose Deficiency Effects of PQS on Guinea Pig PapillaryMuscle in Low Frequency Electrlcal Stimulation