Seisenberger C, Welling A, Schuster A, Hofmann F
Institut für Pharmakologie und Toxikologie der TU München, Germany.
Naunyn Schmiedebergs Arch Pharmacol. 1995 Dec;352(6):662-9. doi: 10.1007/BF00171326.
Stable cell lines are potentially excellent tools for large-scale screening of new compounds. Two carboxyterminal-deleted constructs of the two splice variants a and b of the calcium channel class C alpha 1 subunit were expressed stably in HEK 293 cells. Each cell line produced regular L-type calcium currents. The opening and closing of the calcium channel elicited by potassium depolarization was followed by Fura-2 transients. These transients were blocked by the calcium channel blocker mibefradil with a concentration for 50% inhibition of 1.7 microM. The cell lines expressing the truncated cardiac alpha 1C-a or smooth muscle alpha 1C-b calcium channel were both blocked by nisoldipine under patch clamp conditions. Nisoldipine interacted with higher affinity with the alpha 1C-b channel than with the alpha 1C-a channel. These results indicate that the two cell lines retain the differential dihydropyridine sensitivity of smooth muscle and cardiac calcium channels and may be potential tools for the screening of L-type calcium channel blockers.
稳定细胞系可能是大规模筛选新化合物的优秀工具。钙通道C类α1亚基的两种剪接变体a和b的两个羧基末端缺失构建体在HEK 293细胞中稳定表达。每个细胞系都产生规则的L型钙电流。钾去极化引发的钙通道的开放和关闭伴随着Fura-2瞬变。这些瞬变被钙通道阻滞剂米贝地尔阻断,其50%抑制浓度为1.7微摩尔。在膜片钳条件下,表达截短的心脏α1C-a或平滑肌α1C-b钙通道的细胞系均被尼索地平阻断。尼索地平与α1C-b通道的亲和力高于与α1C-a通道的亲和力。这些结果表明,这两种细胞系保留了平滑肌和心脏钙通道不同的二氢吡啶敏感性,可能是筛选L型钙通道阻滞剂的潜在工具。
