EFFECTS OF ALKALOIDS FROM CORYDALIS-DECUMBENS ON CONTRACTION AND ELECTROPHYSIOLOGY OF CARDIAC MYOCYTES

The chloroform extract of Corydalis decumbens significantly increased the beating amplitude of cultured myocardial cell sheets. Chemical ana lysis led to the isolation of isoquinoline and protopine alkaloids. Of these isolated alkaloids, corlumidine and (+)-adlumidine increased th e beating amplitude, but(+)-egenine decreased the beating rate and bea ting amplitude while protopine did not show any activity. We also stud ied the effects of (+)-egenine and corlumidine on contractile response s and Ca2+ currents in single bullfrog atrial cells using the voltage- clamp method. (+)-Egenine inhibited Ca2+ current by 68% of the control in single cell of bullfrog atrium, while corlumidine increased Ca2+ c urrent to 60% at a concentration of 0.03 mM.