Microtubules are damaged by diethylcarbamazine, anti-filarial drug

Mak et al.（1983）最近报道了一种培养系统，该系统可以使pahangi Brugia的感染幼虫发育到第四阶段。我们利用Mak技术初步研究发现，即使在高浓度（1 mg/ml）下，二乙基氨基马嗪（DEC）也不能在体外杀死pahangi B.幼虫，但能抑制其生长发育。这一结果鼓励我们进一步研究DEC对取食细胞和丝虫幼虫的影响。首先研究了DEC对饲养细胞的影响。本研究使用的细胞为lc - mk_2细胞。DEC抑制了这些细胞的增殖，并且在DEC存在下生长的细胞很可能相互分离并变得圆形。这些结果鼓励我们对细胞质微管复合体进行研究。免疫荧光显微镜显示，暴露于DEC的细胞缺乏细胞质微管复合物的精细模式。随后，利用猪脑制备的微管蛋白进一步研究了DEC对微管的影响。DEC在体外抑制微管的组装和预组装微管的拆卸。当重组或拆解后的产物在DEC存在下用电子显微镜检查时；带状微管是常见的。这些结果强烈表明，DEC破坏了体外支持丝虫幼虫发育的饲养细胞的功能。其次，初步研究了DEC对丝状微管的影响。在没有饲料细胞的情况下，用DEC体外预孵育感染幼虫，然后接种到禽类中。每隔一段时间对这些动物进行尸检，并检查其幼虫的发育情况。暴露于DEC的幼虫不能存活很长时间，也不能发育。由于我们知道DEC在体外对幼虫有直接作用，所以我们要解决的问题是DEC是否会对丝虫器官和组织中富含微管的特定器官——两栖类、节肢动物和排泄细胞造成损害。少

Mak et al. (1983) recently reported an culture system that allows the infective larvae of Brugia pahangi to develop to the fourth stage. Our preliminary study by using the technique of Mak suggested that diethylcarbamazine (DEC) does not kill the larvae of B. pahangi in vitro, even at a high concentration (1 mg/ml), but it inhibits the growth and development of larvae. This results encouraged us to examine the effect of DEC on the feeder cells and filarial larvae.Firstly the effect of DEC on the feeder cells was studied. The cells used in our study were LLC-MK_2 cells. DEC inhibited proliferation of these cells, and cells grown in the presence of DEC were likely to separate from each other and became round in shape. These results encouraged us to study the cytoplasmic microtubules complex. Immunofluorescence microscopy revealed that the cells exposed to DEC were devoid of the delicate pattern of the cytoplasmic microtubules complex. Subsequently, the effect of DEC on microtubules was s … More tudied by using microtubule protein prepared from porcine brain. DEC inhibited assembly of microtubules and disassembled preformed microtubules in vitro. When the reassembled or disassembled products were examined in the presence of DEC by electron microscopy; ribbon-microtubules were frequently observed. These results strongly suggest that DEC disrupts the function of the feeder cells which support the development of filarial larvae in vitro.Secondly, a preliminary study was designed to know the effect of DEC on filasial microtubules. The infective larvae were pre-incubated with DEC in vitro in the absence of feede cells and then inoculated into jirds. The animals were necropsied at a given intervals and the larvae recovered were examined for development. The larvae exposed to DEC did not survive long, nor develop. As we know that DEC has direct effect on larvae in vitro, the problem to be solved is whether DEC gives any damage on amphids, phasmids and excretory cells, the specific organs which are rich in microtubules among the organs and tissues of filarial worms. Less