摘要
The effects of iodium-heterocyclic compound（3,6-di-[dimethytamino]-dibcnzopyrodoniun formate,IHC-64）on the action potentials and contractile force of the isolatedguinca pig papillary muscles were investigatad.50 μmol/L IHC-64 only inhibited contractile forceand had no effect on APA,dv/dt max,APD<sub>5</sub>0 and APD<sub>9</sub>0 of fast action potentials in Tyrode’s so-lution.All of these parametres were depressed by further increasing concentration of IHC-64.InK-rich Tyrodc’s solution,the depressive action of IHC-64 on slow action potentials andcontractile force could be antagonized by incrcased extracellular calcium.These results suggesr thatIHC-64 inhibit not only slow calcium influx but also fast sodium influx,and it may.（?）new calci-urn channd blockcr.
The effects of iodium-heterocyclic compound(3,6-di-[dimethytamino]- dibcnzopyrodoniun formate,IHC-64)on the action potentials and contractile force of the isolated guinca pig papillary muscles were investigatad.50 μmol/L IHC-64 only inhibited contractile force and had no effect on APA,dv/dt max,APD_50 and APD_90 of fast action potentials in Tyrode's so- lution.All of these parametres were depressed by further increasing concentration of IHC-64.In K-rich Tyrodc's solution,the depressive action of IHC-64 on slow action potentials and contractile force could be antagonized by incrcased extracellular calcium.These results suggesr that IHC-64 inhibit not only slow calcium influx but also fast sodium influx,and it may.(?)new calci- urn channd blockcr.
