Cheng J S, Wang J L, Lo Y K, Chou K J, Lee K C, Liu C P, Chang H T, Jan C R
Department of Medicine, Kaohsiung Veterans General Hospital, Taiwan.
Hum Exp Toxicol. 2001 Jul;20(7):359-64. doi: 10.1191/096032701680350523.
This study investigated the effect of the anti-anginal drug, fendiline, on intracellular free Ca2+ levels ([Ca2+]i) in HA/ 22 human hepatoma cells by using fura-2 as a fluorescent Ca2+ dye. Fendiline (1-100 microM) increased [Ca2+]i with an EC50 of 25 microM. Removal of extracellular Ca2+ reduced the [Ca2+]i signals by 51 +/- 5%. Fendiline (10 microM)-induced Ca2+ release was abolished by pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor). Inhibition of phospholipase C with 2 microM 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122) did not alter 10 microM fendiline-induced Ca2+ release. Several other calmodulin antagonists, such as phenoxybenzamine (100-200 microM), trifluoperazine (5-50 microM), and fluphenazine-N-chloroethane (2-100 microM), had no effect on [Ca2+]i. Together, it was found that fendiline increased [Ca2+]i in human hepatoma cells by discharging Ca2+ from the endoplasmic reticulum in an inositol 1,4,5-trisphosphate-independent manner and by inducing Ca2+ entry. This effect of fendiline does not appear to be via antagonism of calmodulin.
本研究通过使用fura-2作为荧光钙染料，研究了抗心绞痛药物芬地林对HA/22人肝癌细胞内游离钙水平（[Ca2+]i）的影响。芬地林（1-100微摩尔）使[Ca2+]i升高，半数有效浓度（EC50）为25微摩尔。去除细胞外钙可使[Ca2+]i信号降低51±5%。用1微摩尔毒胡萝卜素（一种内质网钙泵抑制剂）预处理可消除芬地林（10微摩尔）诱导的钙释放。用2微摩尔1-(6-((17β-3-甲氧基雌甾-1,3,5(10)-三烯-17-基)氨基)己基)-1H-吡咯-2,5-二酮（U73122）抑制磷脂酶C不会改变10微摩尔芬地林诱导的钙释放。其他几种钙调蛋白拮抗剂，如酚苄明（100-200微摩尔）、三氟拉嗪（5-50微摩尔）和氟奋乃静-N-氯乙烷（2-100微摩尔），对[Ca2+]i没有影响。综合来看，发现芬地林通过以肌醇1,4,5-三磷酸非依赖方式从内质网释放钙并诱导钙内流，从而增加人肝癌细胞中的[Ca2+]i。芬地林的这种作用似乎不是通过拮抗钙调蛋白实现的。
