摘要
OBJECTIVE:To investigate the effect of didrovaltrate on L-type calcium current(I Ca-L) in rabbit ventricular myocytes.METHODS:We used the whole cell patch clamp recording technique.RESULTS:Didrovaltrate at concentrations of 30 μg/L and 100 μg/L significantly decreased peak I Ca-L(I Ca-Lmax) from(6.01±0.48) pA/pF to(3.45±0.27) pA/pF and(2.16 ± 0.19) pA/pF(42.6% and 64.1%,n=8,P< 0.01),respectively.Didrovaltrate shifted upwards the current-voltage curves of I Ca-L without changing their active,peak and reverse potentials.Didrovaltrate affected the steady-state inactivation of I Ca-L.The half activation potential(V 1/2) was significantly shifted from(-26 ± 2) to(-36 ± 3) mV(n=6,P<0.05),with a significant change in the slope factor(k)(from 8.8 ± 0.8 to 11.1 ± 0.9,n=6,P<0.05).Didrovaltrate did not affect the activation curve.CONCLUSION:Didrovaltrate blocks I Ca-L in a concentration-dependent manner and probably inhibits I Ca-L in its inactive state,which may contribute to its cardiovascular effect.
OBJECTIVE：To investigate the effect of didrovaltrate on L-type calcium current（I Ca-L） in rabbit ventricular myocytes.METHODS：We used the whole cell patch clamp recording technique.RESULTS：Didrovaltrate at concentrations of 30 μg/L and 100 μg/L significantly decreased peak I Ca-L（I Ca-Lmax） from（6.01±0.48） pA/pF to（3.45±0.27） pA/pF and（2.16 ± 0.19） pA/pF（42.6% and 64.1%,n=8,P〈 0.01）,respectively.Didrovaltrate shifted upwards the current-voltage curves of I Ca-L without changing their active,peak and reverse potentials.Didrovaltrate affected the steady-state inactivation of I Ca-L.The half activation potential（V 1/2） was significantly shifted from（-26 ± 2） to（-36 ± 3） mV（n=6,P〈0.05）,with a significant change in the slope factor（k）（from 8.8 ± 0.8 to 11.1 ± 0.9,n=6,P〈0.05）.Didrovaltrate did not affect the activation curve.CONCLUSION：Didrovaltrate blocks I Ca-L in a concentration-dependent manner and probably inhibits I Ca-L in its inactive state,which may contribute to its cardiovascular effect.
基金
Supported by the Chinese National Science Foundation (No.81170090)
the Science Foundation for Distinguished Young Scholars of Fujian Province(No.2009D015)
the Science Foundation for Distinguished Young Scholars of Xiamen(No.3502Z20116009)
the Science Foundation of Science and Technology of the Bureau of Xiamen(No. 3502Z20094006)
