Lok J B, Pollack R J, Donnelly J J
J Parasitol. 1987 Feb;73(1):80-4.
At concentrations of 0.1-100 ng/ml ivermectin inhibited L3-L4 molting by Onchocerca lienalis in vitro. The degree of inhibition was dose-dependent with a significant effect apparent at 0.1 ng/ml and complete inhibition occurring at 100 ng/ml. The ED50 for molt inhibition was 0.19 ng/ml. Molt-inhibiting levels of the drug were not acutely toxic to the worms. In the presence of 10 ng/ml, a concentration giving 95% molt inhibition, motility at day 7 postinoculation was 71% of that seen in nontreated controls. A more pronounced effect on motility was apparent in larvae under long-term cultivation in the presence of ivermectin. Kinetic studies indicated that the majority of the larvae respond irreversibly to the drug within the first 2 hr of exposure. Twenty-four hours of exposure were required for a maximal response. The inhibitory effects of ivermectin were less pronounced if larvae were allowed to develop under normal culture conditions for 24 or more hours prior to the initiation of drug treatment.
在浓度为0.1 - 100 ng/ml时，伊维菌素在体外抑制了盘尾丝虫的L3 - L4期蜕皮。抑制程度呈剂量依赖性，在0.1 ng/ml时即有明显效果，100 ng/ml时出现完全抑制。蜕皮抑制的半数有效剂量（ED50）为0.19 ng/ml。药物的蜕皮抑制水平对虫体无急性毒性。在10 ng/ml（该浓度可产生95%的蜕皮抑制）存在的情况下，接种后第7天的活动力为未处理对照的71%。在伊维菌素存在的情况下，长期培养的幼虫对活动力有更明显的影响。动力学研究表明，大多数幼虫在接触药物的前2小时内对药物产生不可逆反应。需要24小时的接触才能产生最大反应。如果在开始药物治疗前让幼虫在正常培养条件下发育24小时或更长时间，伊维菌素的抑制作用就不那么明显。
