Awad W A, Razzazi-Fazeli E, Böhm J, Zentek J
Department of Veterinary Public Health and Food Science, Institute of Animal Nutrition, University of Veterinary Medicine, Vienna, Austria.
J Anim Physiol Anim Nutr (Berl). 2007 Jun;91(5-6):175-80. doi: 10.1111/j.1439-0396.2007.00689.x.
Deoxynivalenol (DON) decreases glucose absorption in the proximal jejunum of laying hens in vitro and this effect is apparently mediated by the inhibition of the sodium D-glucose co-transporter. DON could modulate the sugar transport of other intestinal regions of chickens. For this purpose, we have measured the effects of DON on the Na(+) D-glucose co-transporter, by addition of DON after and before a glucose addition in the isolated epithelium from chicken duodenum, jejunum, ileum, caecum and colon by using the Ussing chamber technique in the voltage clamp technique. The data showed in all segments of the gut that the addition of D-glucose on the mucosal side produced an increase in the current (Isc) compared with the basal values, the Isc after glucose addition to the small intestine was greater than the Isc of the large intestine compared with the basal values, specially of the jejunum (p < 0.002), indicating that the jejunum is the segment that is the best prepared for Na(+)-D-glucose co-transport. Further addition of 10 microg DON/ml to the mucosal solution decreased the Isc in all segments and the Isc returned to the basal value, especially in the duodenum and mid jejunum (p < 0.05). In contrast, the addition of 5 mmol D-glucose/l on the mucosal side after incubation of the tissues with DON in all segments had no effect on the Isc (p > 0.05), suggesting that DON previously inhibited the Na(+)D-glucose co-transport. The blocking effects of DON in duodenum and jejunum were greater than the other regions of the gut. It can be concluded that the small intestine of laying hens has the most relevant role in the carrier mediated glucose transport and the large intestine, having non-significant capacity to transport sugars, appears to offer a minor contribution to glucose transport because the surface area is small. The effect of D-glucose on the Isc was reversed by DON in all segments, especially in the duodenum and jejunum, suggesting that DON entirely inhibited Na(+)-D-glucose co-transport. This finding indicates that the inhibition of Na(+) co-transport system in all segments could be an important mode of action for DON toxicity of hens.
脱氧雪腐镰刀菌烯醇（DON）在体外可降低蛋鸡空肠近端的葡萄糖吸收，且这种作用显然是由抑制钠 - D - 葡萄糖共转运体介导的。DON可能会调节鸡其他肠道区域的糖转运。为此，我们通过在电压钳技术中使用尤斯灌流小室技术，在鸡十二指肠、空肠、回肠、盲肠和结肠的分离上皮中，在添加葡萄糖之前和之后添加DON，来测量DON对钠（+）- D - 葡萄糖共转运体的影响。数据显示，在肠道的所有节段中，与基础值相比，在黏膜侧添加D - 葡萄糖会使电流（Isc）增加，与基础值相比，小肠添加葡萄糖后的Isc大于大肠的Isc，特别是空肠（p < 0.002），这表明空肠是最适合钠（+）- D - 葡萄糖共转运的节段。在黏膜溶液中进一步添加10微克DON/毫升会降低所有节段的Isc，且Isc恢复到基础值，特别是在十二指肠和空肠中段（p < 0.05）。相反，在所有节段中，用DON孵育组织后在黏膜侧添加5毫摩尔D - 葡萄糖/升对Isc没有影响（p > 0.05），这表明DON先前抑制了钠（+）- D - 葡萄糖共转运。DON在十二指肠和空肠中的阻断作用大于肠道的其他区域。可以得出结论，蛋鸡的小肠在载体介导的葡萄糖转运中起最相关的作用，而大肠转运糖的能力不显著，似乎对葡萄糖转运的贡献较小，因为其表面积较小。在所有节段中，DON都使D - 葡萄糖对Isc的影响逆转，特别是在十二指肠和空肠中，这表明DON完全抑制了钠（+）- D - 葡萄糖共转运。这一发现表明，抑制所有节段中的钠（+）共转运系统可能是DON对母鸡产生毒性的重要作用方式。
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