Zhou Hong-Yi, Wang Fang, Cheng Lan, Fu Li-Ying, Zhou Ji, Yao Wei-Xing
Department of Pharmacology,Tongji medical college of Huazhong university of science and technology, Wuhan 430030, Hubei Province, China.
World J Gastroenterol. 2003 Jan;9(1):134-6. doi: 10.3748/wjg.v9.i1.134.
To study the effects of tetrandrine (Tet) on calcium release-activated calcium current (I(CRAC)), delayed rectifier potassium current (I(K)), and inward rectifier potassium currents (I(K1)) in isolated rat hepatocytes.
Hepatocytes of rat were isolated by using perfusion method. Whole cell patch-clamp techniques were used in our experiment.
The peak amplitude of I(CRAC) was -508+/-115 pA (n=15), its reversal potential of I(CRAC) was about 0 mV. At the potential of -100 mV, Tet inhibited the peak amplitude of I(CRAC) from -521+/-95 pA to -338+/-85 pA (P<0.01 vs control, n=5), with the inhibitory rate of 35 % at 10 micromol/L and from -504+/-87 pA to -247+/-82 pA (P<0.01 vs control, n=5), with the inhibitory rate of 49 % at 100 micromol/L, without affecting its reversal potential. The amplitude of I(CRAC) was dependent on extracellular Ca(2+) concentration. The peak amplitude of I(CRAC) was -205+/-105 pA (n=3) in tyrode's solution with Ca(2+) 1.8 mmol/L (P<0.01 vs the peak amplitude of I(CRAC) in external solution with Ca(2+) 10 mmol/L). Tet at the concentration of 10 and 100 micromol/L did not markedly change the peak amplitude of delayed rectifier potassium current and inward rectifier potassium current (P>0.05 vs control).
Tet protects hepatocytes by inhibiting I(CRAC), which is not related to I(K) and I(K1).
研究粉防己碱（Tet）对分离的大鼠肝细胞中钙释放激活钙电流（I(CRAC)）、延迟整流钾电流（I(K)）和内向整流钾电流（I(K1)）的影响。
采用灌注法分离大鼠肝细胞。实验中使用全细胞膜片钳技术。
I(CRAC)的峰值幅度为-508±115 pA（n = 15），其反转电位约为0 mV。在-100 mV电位下，Tet将I(CRAC)的峰值幅度从-521±95 pA抑制至-338±85 pA（与对照组相比，P<0.01，n = 5），在10 μmol/L时抑制率为35%；从-504±87 pA抑制至-247±82 pA（与对照组相比，P<0.01，n = 5），在100 μmol/L时抑制率为49%，且不影响其反转电位。I(CRAC)的幅度依赖于细胞外Ca(2+)浓度。在含1.8 mmol/L Ca(2+)的台氏液中，I(CRAC)的峰值幅度为-205±105 pA（n = 3）（与含10 mmol/L Ca(2+)的外部溶液中I(CRAC)的峰值幅度相比，P<0.01）。10和100 μmol/L浓度的Tet对延迟整流钾电流和内向整流钾电流的峰值幅度无明显影响（与对照组相比，P>0.05）。
Tet通过抑制I(CRAC)保护肝细胞，这与I(K)和I(K1)无关。
