Loos Michaela, Hellemans Ann, Cox Eric
Laboratory of Veterinary Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
Vet Immunol Immunopathol. 2013 Mar 15;152(1-2):82-6. doi: 10.1016/j.vetimm.2012.09.014. Epub 2012 Sep 26.
Enterotoxigenic Escherichia coli (ETEC) are a major cause of infectious diarrhea both in human and pigs. After ingestion of contaminated food or water, ETEC bacteria colonize the small intestine where they produce heat-labile (LT) and/or heat-stable (ST) enterotoxins, which induce watery diarrhea. We investigated the possibility of eliciting STa-induced secretion in jejunal segments of anesthetized pigs using a small-intestinal segment perfusion (SISP) model. Five consecutive mid-jejunal segments of anaesthetized piglets were perfused for 6h with different concentrations of STa in a physiologic salt solution. Changes in intestinal net fluid absorption were measured. From the results we could conclude that the STa response was dose-dependent and that continuous perfusion with 50 nM of STa or more was required to reduce net absorption. This concentration was sufficient to reduce net absorption compared to control segments in 12 out of 14 piglets. STa-induced responses however showed relative high variation between different jejunal segments of one pig, similar to the inter-segment variation seen in control animals where segments were perfused with physiologic salt solution. These results indicate that more optimization is required before this model could be used to test compounds that could interfere with the STa-induced fluid secretion.
产肠毒素大肠杆菌（ETEC）是人类和猪传染性腹泻的主要病因。摄入受污染的食物或水后，ETEC细菌定殖于小肠，在那里产生不耐热（LT）和/或耐热（ST）肠毒素，引发水样腹泻。我们使用小肠段灌注（SISP）模型研究了在麻醉猪的空肠段引发STa诱导分泌的可能性。将麻醉仔猪的五个连续空肠中段用不同浓度的STa在生理盐溶液中灌注6小时。测量肠道净液体吸收的变化。从结果我们可以得出结论，STa反应呈剂量依赖性，并且需要用50 nM或更高浓度的STa连续灌注才能减少净吸收。与14只仔猪中的12只的对照段相比，该浓度足以减少净吸收。然而，STa诱导的反应在一只猪的不同空肠段之间表现出相对较高的变异性，类似于在对照动物中用生理盐溶液灌注段时观察到的段间变异性。这些结果表明，在该模型可用于测试可能干扰STa诱导的液体分泌的化合物之前，还需要更多优化。
