Sheriff James C, Kotze Andrew C, Sangster Nicholas C, Hennessy Desmond R
CSIRO Livestock Industries, Clunies Ross Street, Prospect, NSW 2148, Australia; Faculty of Veterinary Science, University of Sydney, NSW 2006, Australia.
Vet Parasitol. 2005 Mar 31;128(3-4):341-6. doi: 10.1016/j.vetpar.2004.12.008. Epub 2005 Jan 22.
While several in vitro studies have shown that the anthelmintic ivermectin inhibits feeding by parasites, the relevance of this putative site of action in vivo has not been demonstrated. For this study, techniques to measure feeding by Haemonchus contortus in vivo relied on the blood feeding characteristics of the worm, and utilised tritiated inulin administered to sheep intravenously and subsequently measured in worms recovered from abomasa. Nematodes recovered from sheep treated with ivermectin 4 h prior to the [3H]inulin administration showed equivalent feeding levels (over a 1 h period) to those recovered from sheep not treated with ivermectin. In addition, there was no difference in the radioactivity in nematodes of an ivermectin-susceptible and an ivermectin-resistant isolate recovered from individual sheep with concurrent infections after a dose with ivermectin. Ivermectin, therefore, had no effect on feeding by H. contortus in vivo under these experimental conditions. The results are discussed in relation to the dynamics of the expulsion of H. contortus from sheep following ivermectin treatment.
虽然多项体外研究表明驱虫药伊维菌素可抑制寄生虫的摄食，但这一假定作用位点在体内的相关性尚未得到证实。在本研究中，测量捻转血矛线虫体内摄食的技术依赖于该蠕虫的吸血特性，并利用静脉注射给绵羊的氚标记菊粉，随后在从真胃中回收的蠕虫中进行测量。在给予[3H]菊粉前4小时用伊维菌素处理的绵羊体内回收的线虫，其摄食水平（在1小时内）与未用伊维菌素处理的绵羊体内回收的线虫相当。此外，在同时感染的个体绵羊经伊维菌素剂量处理后，从其体内回收的伊维菌素敏感株和伊维菌素耐药株线虫的放射性没有差异。因此，在这些实验条件下，伊维菌素对捻转血矛线虫在体内的摄食没有影响。结合伊维菌素治疗后捻转血矛线虫从绵羊体内排出的动态情况对结果进行了讨论。
