NNC 55-0396 [(1S, 2S)-2-(2-(N-[(3-benzimidazol-2-yl) propyl]-N-methylamino)ethyl)-6-fluoro-1,2,3,4-tetrahydro-1-isopropyl-2-naphtyl cyclopropanecarboxylate dihydrochloride]:: A new selective inhibitor of T-type calcium channels
NNC 55-0396 [(1S, 2S)-2-(2-(N-[(3-benzimidazol-2-yl) propyl]-N-methylamino)ethyl)-6-fluoro-1,2,3,4-tetrahydro-1-isopropyl-2-naphtyl cyclopropanecarboxylate dihydrochloride]:: A new selective inhibitor of T-type calcium channels
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DOI：
10.1124/jpet.103.060814
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发表时间：
2004-04-01
影响因子：
3.5
通讯作者：
Li, M
中科院分区：
文献类型：
--
作者：
Huang, LP;Keyser, BM;Li, M
米贝拉地尔是一种钙通道拮抗剂，可抑制T型和高电压激活的钙通道。我们以前表明，通过细胞内水解产生活性代谢物，发生由米贝拉地尔阻断高电压激活的通道。在本研究中，我们修改了米贝拉地尔的结构，开发了一种非水解类似物，（1 S，2S）-2-（2-（N-[（3-苯并咪唑-2-基）丙基]-N-甲氨基）乙基）-6-氟-1，2，3，4-四氢-1-异丙基-2-萘基环丙烷甲酸酯二盐酸盐（NNC 55-0396），对T型通道产生选择性抑制作用。NNC 55-0396阻断人胚肾293细胞中重组α（1）G T型通道的急性IC 50与7 μ M相似，而100 μ M NNC 55-0396对INS-1细胞中的高压激活通道没有可检测到的影响。NNC 55-0396不影响T型Ca 2+电流的电压依赖性激活，但改变了稳态失活曲线的斜率。阻断T-型Ca ~（2+）电流部分缓解膜超极化和增强在高刺激频率。将NNC 55-0396从记录室中冲洗出来并未逆转T型Ca 2+电流活性，表明该化合物溶解在质膜中或通过质膜发挥其作用;然而，该化合物的细胞内灌注并未阻断T型Ca 2+电流，这与细胞质作用途径相反。将胰岛素分泌细胞系（INS-1）的细胞与NNC 55-0396孵育20 min后，质谱法未检测到引起L型Ca 2+通道抑制的米贝拉地尔代谢产物。我们得出结论，NNC 55-0396由于其结构修饰，不会产生导致L型Ca（2+）通道抑制的代谢产物，因此对T型Ca（2+）通道更具选择性。
Mibefradil is a Ca2+ channel antagonist that inhibits both T-type and high-voltage-activated Ca2+ channels. We previously showed that block of high-voltage-activated channels by mibefradil occurs through the production of an active metabolite by intracellular hydrolysis. In the present study, we modified the structure of mibefradil to develop a nonhydrolyzable analog, (1S,2S)-2-(2-(N-[(3-benzimidazol-2-yl)propyl]-N-methylamino) ethyl)-6-fluoro-1,2,3,4-tetrahydro-1-isopropyl-2-naphtyl cyclopropanecarboxylate dihydrochloride (NNC 55-0396), that exerts a selective inhibitory effect on T-type channels. The acute IC50 of NNC 55-0396 to block recombinant alpha(1)G T-type channels in human embryonic kidney 293 cells was similar to7 muM, whereas 100 muM NNC 55-0396 had no detectable effect on high-voltage- activated channels in INS-1 cells. NNC 55-0396 did not affect the voltage-dependent activation of T-type Ca2+ currents but changed the slope of the steady-state inactivation curve. Block of T-type Ca2+ current was partially relieved by membrane hyperpolarization and enhanced at a high-stimulus frequency. Washing NNC 55-0396 out of the recording chamber did not reverse the T-type Ca2+ current activity, suggesting that the compound dissolves in or passes through the plasma membrane to exert its effect; however, intracellular perfusion of the compound did not block T-type Ca2+ currents, arguing against a cytoplasmic route of action. After incubating cells from an insulin-secreting cell line (INS-1) with NNC 55-0396 for 20 min, mass spectrometry did not detect the mibefradil metabolite that causes L-type Ca2+ channel inhibition. We conclude that NNC 55-0396, by virtue of its modified structure, does not produce the metabolite that causes inhibition of L-ype Ca(2+)channels, thus rendering it more selective to T-type Ca(2+)channels.