Yahara I, Harada F, Sekita S, Yoshihira K, Natori S
J Cell Biol. 1982 Jan;92(1):69-78. doi: 10.1083/jcb.92.1.69.
To compare the effects of cytochalasins on the cellular level with those on the molecular level, 24 cytochalasins, 20 natural compounds and 4 derivatives, were used. The following effects were tested for each of 24 cytochalasins; (a) four high dose (2-20 muM) effects on the cellular level: rounding up of fibroblastic cells, contraction of actin cables, formation of hairy filaments containing actin, and inhibition of lymphocyte capping; (b) a low dose (0.2-2 muM) effect: inhibition of membrane ruffling; and (c) two in vitro effects: an inhibition of actin filament elongation (the high affinity effect [low dose effect] in vitro) and an effect on viscosity of actin filaments(the low affinity effect [high dose effect] in vitro). These results indicated that there are almost the same hierarchic orders of relative effectiveness of different cytochalasins between low and high dose effects and between cellular and molecular effects. From the data obtained with the 24 cytochalasins, we have calculated correlation coefficients of 0.87 and 0.79 between an effect in vivo, inhibition of capping, and an effect in vitro, inhibition of actin filament elongation, as well as between inhibition of capping and another effect in vitro, effect on viscosity of actin filaments, respectively. Furthermore, a correlation coefficient between the high affinity effect and the low affinity effect determined in vitro was calculated to be 0.90 from the data obtained in this study. The strong positive correlation among low and high dose effects in vivo and those in vitro suggests that most of the effects caused by a cytochalasin, irrespective of doses or affected phenomena, might be attributed to the interaction between the drug and the common target protein, actin. In the course of the immunofluorescence microscope study on cytochalasin-treated cells using actin antibody, we have found that aspochalasin D, a 10-isopropylcytochalasin, strongly induced the formation of rodlets containing actin in the cytoplasm of the treated fibroblasts. In contrast, the other cytochalasins, including cytochalasin B, cytochalasin C, cytochalasin D, and cytochalasin H, were found to induce the formation of nuclear rodlets. Both cytoplasmic and nuclear rodlets found in the cytochalasin-treated cells were similar in ultrastructures to those induced by 5 to 10 percent (vol/vol) dimethyl sulfoxide in the same type of cells.
为了比较细胞松弛素在细胞水平和分子水平上的作用效果，使用了24种细胞松弛素、20种天然化合物和4种衍生物。对24种细胞松弛素中的每一种都测试了以下效果：(a) 四种高剂量（2 - 20 μM）对细胞水平的影响：成纤维细胞变圆、肌动蛋白丝收缩、含有肌动蛋白的毛状丝形成以及淋巴细胞帽化的抑制；(b) 低剂量（0.2 - 2 μM）的影响：膜皱褶的抑制；(c) 两种体外效果：肌动蛋白丝伸长的抑制（体外高亲和力效应[低剂量效应]）和对肌动蛋白丝粘度的影响（体外低亲和力效应[高剂量效应]）。这些结果表明，不同细胞松弛素在低剂量和高剂量效应之间以及在细胞和分子效应之间的相对有效性几乎具有相同的等级顺序。根据用24种细胞松弛素获得的数据，我们分别计算了体内效应（帽化抑制）和体外效应（肌动蛋白丝伸长抑制）之间以及帽化抑制和另一种体外效应（对肌动蛋白丝粘度的影响）之间的相关系数，分别为0.87和0.79。此外，根据本研究获得的数据，计算出体外测定的高亲和力效应和低亲和力效应之间的相关系数为0.90。体内低剂量和高剂量效应与体外效应之间的强正相关表明，细胞松弛素引起的大多数效应，无论剂量或受影响的现象如何，可能都归因于药物与共同靶蛋白肌动蛋白之间的相互作用。在用肌动蛋白抗体对细胞松弛素处理的细胞进行免疫荧光显微镜研究的过程中，我们发现，10 - 异丙基细胞松弛素阿索松弛素D在处理过的成纤维细胞的细胞质中强烈诱导含有肌动蛋白的小杆的形成。相反，发现包括细胞松弛素B、细胞松弛素C、细胞松弛素D和细胞松弛素H在内的其他细胞松弛素会诱导核小杆的形成。在细胞松弛素处理的细胞中发现的细胞质和核小杆在超微结构上与在相同类型细胞中由5%至10%（体积/体积）二甲基亚砜诱导的小杆相似。
