DDPH inhibited L-type calcium current and sodium current in a single ventricular myocyte of guinea pig

摘要

(1)DDPH(3-300μmol.L~-1)decreased I_Ca at 0 mV in a concentration-dependent manner with an IC_50 value of 28.5μmol.L~-1(95/100 confidence limits: 14.3-42.7μmol.L~-1, n=8 cells from 8 guinea pigs). Verapamil(0.3-30μmol.L~-1)reduced I_Ca with an IC_50 value of 1.8μmol.L~-1(95/100 confidence limits: 1.3-2.3μmol.L~-1, n=6 cells from 6 guinea pigs). Mexiletine 100μmol.L~-1 did not affect I_Ca(n= 5 cells from 5 guinea pigs, P < 0.05). DDPH exhibitory inhibito- Ry effects on both I_Ca and I_Na, but its inhibitory effect on I_Ca was weaker than verapamil and on I_Na was weaker Than mexiletine.