Objective To investigate the effect of Tetrandrine(Tet) in different concentrations on Cardiac Noradrenaline(NE) Release
and Metabolize Induced by Electrical Field Stimulation in isolated perfused gunia pig hearts under ischemic
conditions.Methods Method High-performance liquid chromatography(HPLC) with electrochemical detection was used to determine the outflow of cardiac NE and dihydroxyphenylglycol(DHPG) from perfused guinea pig hearts. Electrical field stimulations were applied twice(S_1 ,S_2 ) under different conditions.Results Tet revealed a
concentration dependent decrease of NE release at concentrations of 10 μmol/L , 30 μmol/L , 80 μmol/L under ischemic conditions ( P < 0.05 ).There was no statistical difference in DHPG release between ischemic,whereas the release of DHPG was markly increased in middle and high concentration group( P < 0.05 ).Conclusion Tet was able to inhibit the cardiac exocytotic NE release in isolated perfused gunia pig hearts under ischemic conditions.In middle and high concentration,it can even accelerate the metabolizing of the axoplasmic NE. Those effects of Tet were related with its concentration.