EFFECTS OF PALMATINE ON ELECTROPHYSIOLOGICAL CHARACTER IN THE ISOLATED GUINEA PIG PAPILLARY MUSCLES / 中国药理学通报

ABSTRACT

The mechanism of antiarrhythmic effects of palmatine( Pal), an benzoquinolizine compound were studied in experimental animals.In the isolated guinea pig papillary muscles, Pal 50 ?mol/L markedly prolonged the functional refractory period(FRP)and decreased the automaticity induced by adrenaline, but exerted no effect on excitabj- iity and contractility of the muscles.Pal(10 ?mol/L ) prolonged both APD20 and APD90 of the action potential of guinoa pig papillary muscles. The Vmax was decreased at 100 ?mol/L Pal, but the action potential amplitude( APA ) and resting potential ( RP ) were unaltered.The antiarrhythmic action of Pal may be due to its ability to decrease automaticity and to proloagate FRP and APD of the myocardium.