This experiment used whole-cell patch-clamp technique to investigate the course of recovery from use-dependent block of Na+ channels (Nav 1.5) in human embryonic kidney (HEK) cells, on which to verify the effects of v...This experiment used whole-cell patch-clamp technique to investigate the course of recovery from use-dependent block of Na+ channels (Nav 1.5) in human embryonic kidney (HEK) cells, on which to verify the effects of volatile oil of Nardostachy chinesis Batal (Gansong). Methods Two pulses generated by computer followed by a recovery pulse and a test pulse, the interval duration between the two pulses varied from 16 ms to 1 s, and holding potential is -80 mV to -140 mV. The peak Na+ current for a given recovery time was normalized to the fully recovered peak current, and the normalized value was the plot as a function of the recovery time to study the effects of 3 ppm concentration Gansong volatile oil on recovery from use-dependent block of Nav1.5 in HEK. Results It showed that Gansong group, comparing with control group, delayed the time courses of recovery from use-dependent block [(33.2±5.77) ms for control group and (52.5±6.08) ms for 3 ppm Gansong group, P<0.05]. In the presence of Gansong, inhibition of the Na+ current was enhanced by increasing frequency of depolarizing pulse from 56.5 ms to 16 ms. In the control group, the time course of recovery showed that recovery started at 19.5 ms and finished by 36.5 ms. In the presence of Gansong, the time course of recovery showed that recovery started at 36.5 ms and finished by 56.5 ms. Na+ currents recovered from the use-dependent block varying with holding potential (holding potential-dependent). Conclusions The results suggested that Na+ currents recovered from the use-dependent block correlated with persistent time, holding potential. The Gansong volatile oil has inhibitive effect on the Na+ current recovery.展开更多
基金National Natural Science Foundation of People's Republic of China(No.30660060)
文摘This experiment used whole-cell patch-clamp technique to investigate the course of recovery from use-dependent block of Na+ channels (Nav 1.5) in human embryonic kidney (HEK) cells, on which to verify the effects of volatile oil of Nardostachy chinesis Batal (Gansong). Methods Two pulses generated by computer followed by a recovery pulse and a test pulse, the interval duration between the two pulses varied from 16 ms to 1 s, and holding potential is -80 mV to -140 mV. The peak Na+ current for a given recovery time was normalized to the fully recovered peak current, and the normalized value was the plot as a function of the recovery time to study the effects of 3 ppm concentration Gansong volatile oil on recovery from use-dependent block of Nav1.5 in HEK. Results It showed that Gansong group, comparing with control group, delayed the time courses of recovery from use-dependent block [(33.2±5.77) ms for control group and (52.5±6.08) ms for 3 ppm Gansong group, P<0.05]. In the presence of Gansong, inhibition of the Na+ current was enhanced by increasing frequency of depolarizing pulse from 56.5 ms to 16 ms. In the control group, the time course of recovery showed that recovery started at 19.5 ms and finished by 36.5 ms. In the presence of Gansong, the time course of recovery showed that recovery started at 36.5 ms and finished by 56.5 ms. Na+ currents recovered from the use-dependent block varying with holding potential (holding potential-dependent). Conclusions The results suggested that Na+ currents recovered from the use-dependent block correlated with persistent time, holding potential. The Gansong volatile oil has inhibitive effect on the Na+ current recovery.
