EFFECTS OF OSTHOLE ON THE PHYSIOLOGICAL PROPERTIES IN THE ISOLATED AURICLE OF GUINEA PIG / 西安交通大学学报(医学版)

Osthole, the coumarin isolated from the fruits of Cnidum monnieri (L.) Cusson. The effects of osthole on the physiological properties in isolated auricle of guinea pig were studied. It possesses dose—dependent negative inotropic effects, the BaCl_2 inducing automaticity was inhibited, and the functional refractory period (FRP) was prolonged, and the frequence of sinoatrial node was slowed The negative inotropism and automatism suggest that sothole mey be antagonis tic to Ca~(2+), while the decrease of excitability and the prolongation of FRP indicate that it may be due to its inhibition on Na~+ current. The decrease of automaticity and excitability and prolongation of FRP are thought to be its antiarrhythmic action.