Douch P G, Morum P E
Wallaceville Animal Research Centre, Upper Hutt, New Zealand.
Int J Parasitol. 1994 May;24(3):321-6. doi: 10.1016/0020-7519(94)90078-7.
The anthelmintics ivermectin, levamisole, morantel tartrate and thiabendazole all inhibited, in vitro, the motility of third stage larvae (L3) of Trichostrongylus colubriformis. The bioassay, based on the inhibition of L3 migration from agar gels, yielded sigmoid dose-response curves for ivermectin, levamisole and morantel tartrate, but not thiabendazole. The concentration of levamisole giving 50% inhibition of migration (EC50) was determined for Cooperia curticei, Haemonchus contortus, Nematodirus spathiger, Ostertagia circumcincta, Trichostrongylus axei, T. colubriformis and T. vitrinus. EC50s differed between species but within species the EC50s for ensheathed and exsheathed L3 were similar except for N. spathiger which showed significantly higher EC50 for the ensheathed L3. No difference between EC50s for levamisole-resistant and susceptible strains of T. colubriformis were found. Similarly, morantel-resistant and susceptible strains of T. colubriformis could not be differentiated in this bioassay. The inhibition of L3 motility by known anthelmintic compounds in this bioassay suggests that the bioassay could be used as a screen for potential new anthelmintics.
抗蠕虫药伊维菌素、左旋咪唑、噻嘧啶和噻苯达唑在体外均能抑制蛇形毛圆线虫第三期幼虫（L3）的活动。基于L3从琼脂凝胶中迁移受抑制的生物测定法，伊维菌素、左旋咪唑和噻嘧啶呈现出S形剂量反应曲线，而噻苯达唑则未呈现。测定了左旋咪唑对柯氏古柏线虫、捻转血矛线虫、斯氏类圆线虫、环形奥斯特线虫、斧形毛圆线虫、蛇形毛圆线虫和玻璃样毛圆线虫的50%迁移抑制浓度（EC50）。不同物种的EC50有所不同，但在同一物种内，带鞘和去鞘L3的EC50相似，不过斯氏类圆线虫的带鞘L3的EC50显著更高。未发现蛇形毛圆线虫左旋咪唑抗性和敏感品系的EC50有差异。同样，在此生物测定法中无法区分蛇形毛圆线虫噻嘧啶抗性和敏感品系。在此生物测定法中已知抗蠕虫化合物对L3活动的抑制表明该生物测定法可作为潜在新型抗蠕虫药的筛选方法。
