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采用双微电极电压钳制术研究３，６－（二甲氨基）－二苯骈碘杂环依地酸盐（ＩＨＣ－７２）对家兔心室浦肯野纤维慢内向电流（Ｉｓｉ）的电压和频率依赖性阻滞效应。将控制电位（Ｅｃ）置于－５ｍＶ，维持电位（Ｅｈ）分别置于－３５，－３０，－２０ｍＶ时，１０１．６μｍｏｌ／ＬＩＨＣ－７２灌流２０ｍｉｎ前后的峰值Ｉｓｉ分别从７８．７５±１４．３３，４０．６３±５．６３，１８．８±３．５４ｎＡ降至４９．３８±１０．８４，１９．３８±５．６３，２．５±２．６７ｎＡ，抑制率分别为３７．３％，５２．３％，８６．７％（Ｐ均＜０．０１）。用０．１２５，０．２，０．５Ｈｚ频率分别刺激１０１．６μｍｏｌ／ＬΙΗＣ－７２灌流２０ｍｉｎ前后的标本，峰值Ｉｓｉ从灌流前的７５．３８±１４．０２，７５．６４±１３．８６，７４．９８±１３．１２ｎＡ降至５８．７５±９．５４，３４．３８±１０．１６，２１．２５±１１．２６ｎＡ，抑制率分别为２２．１％，５４．５％，７１．７％，Ｐ均＜０．０１。结果提示：ＩＨＣ－７２对心肌细胞慢钙通道具有电压和频率依赖性阻滞效应。
Dual-electrode voltage clamp technique was used to study the effects of 3,6-dimethylaminodiphenyloxododecanedioate edetate (IHC-72) on the slow inward current (Isi) of rabbit ventricular Purkinje fibers Frequency dependent blockade effect. When the control potential (Ec) was set at -5mV and the holding potential (Eh) were set at -35, -30 and -20mV respectively, the peak Isi of 101.6μmol / LIHC-72 before and after 20min perfusion was 78.75 ± 14 respectively. 33,40.63 ± 5.63,18.8 ± 3.54nA to 49.38 ± 10.84, 19.38 ± 5.63,2.5 ± 2.67nA, the inhibition rates were 37.3 %, 52.3%, 86.7% respectively (all P <0.01). The frequencies of 101.6μmol / L IHC-72 perfusion 20min before and after perfusion with 0.125,0.2,0.5Hz frequency peak, the peak Isi from pre-perfusion 75.38 ± 14.02,75.64 ± 13.86, 74.98 ± 13.12nA to 58.75 ± 9.54,34.38 ± 10.16,21.25 ± 11.26nA, the inhibition rates were 22.1%, 54.5%, 71.7 %, P <0.01. The results suggest that IHC-72 has a voltage-dependent and frequency-dependent block effect on myogenic calcium channel.