ABSTRACT
AIM To investigate the effects of levo phenoprolamine hydrochloride [ levo 1 (2,6 dimethylphenoxy) 2 (3,4 dimethoxyphenyl ethylamino) propane hydrochloride] [ l DDPH([?]D 25 1 08)]on experimental arrhythmias. on experimental arrhythmias. METHODS Intravenous administration of ouabain, aconitine or CaCl 2 induced arrhythmias in rats or guinea pigs; Microelectrode recording was used to record action potential; Whole cell patch clamp technique was used to record L type calcium current ( I Ca,L ). RESULTS ① l DDPH 50 mg?kg -1 inhibited the ventricular arrhythmias induced by intravenous injection of ouabain in guinea pigs or aconitine and CaCl 2 in rats. ② l DDPH 30 ?mol?L -1 shortened 50% action potential duration (APD 50 ) and prolonged effective refractory period (ERP) ( n =6, P