Acidosis and lipopolysaccharide from Escherichia coli B:055 cause hyperpermeability of rumen and colon tissues
Acidosis and lipopolysaccharide from Escherichia coli B:055 cause hyperpermeability of rumen and colon tissues
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DOI：
10.3168/jds.2007-0257
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发表时间：
2007-12-01
影响因子：
3.5
通讯作者：
Ametaj, B. N.
中科院分区：
文献类型：
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作者：
Emmanuel, D. G. V.;Madsen, K. L.;Ametaj, B. N.
本研究的目的是评估酸性pH值的灌流液和脂多糖（LPS）的存在下，对瘤胃和结肠粘膜组织的渗透性甘露醇和LPS使用的Ussing室系统的影响。从屠宰的饲养场公牛中获得的瘤胃和结肠组织（n = 8）在pH为4.5、5.5和6.5（瘤胃）和pH为5.5、6.5和7.4（结肠）的条件下，在有或没有来自大肠杆菌B：055的LPS（500 μ g/mL）的情况下，测试了H-3-甘露醇渗透性的变化。将10 μ L（525.4 GBq/mmol）的3 H-甘露醇加入到Ussing室的粘膜侧，以检测渗透性的变化，并在20、25、30和35分钟时从血清侧采集4份样品。在酸性pH值为4.5和5.5以及存在500 μ g/mL LPS时，瘤胃和结肠粘膜对3 H-甘露醇的渗透性分别增加6倍和5倍。与此相反，LPS并没有影响瘤胃和结肠的渗透性在pH值范围从5.5和7.4。LPS在牛的瘤胃和结肠粘膜中的转运不依赖于pH。如果存在于粘膜侧，则LPS会通过这些组织移位。总之，在LPS存在下和酸性pH下，瘤胃和结肠组织对3 H-甘露醇的渗透性增加，而LPS渗透通过粘膜组织与灌注液的pH无关。进一步的研究是必要的，以了解的机制（S）的酸性pH值的瘤胃粘膜和LPS的存在下，使瘤胃和结肠组织“渗漏”。
The objective of the present investigation was to evaluate the effects of acidic pH of the perfusate and presence of lipopolysaccharide (LPS) on permeability of rumen and colon mucosal tissues to mannitol and LPS using the Ussing chamber system. Rumen and colon tissues (n = 8), obtained from slaughtered feedlot steers, were tested for changes in permeability to H-3- mannitol under pH of 4.5, 5.5, and 6.5 for rumen and at 5.5, 6.5, and 7.4 for colon, with or without LPS from Escherichia coli B: 055 at 500 mu g/mL. The 3H- Mannitol was added at 10 mu L (525.4 GBq/mmol) on the mucosal side of the Ussing chamber to detect changes in permeability, and 4 samples were taken at 20, 25, 30, and 35 min from the serosal side. Permeability of rumen and colon mucosa to 3H- mannitol increased 6- and 5- fold, respectively, at acidic pH values of 4.5 and 5.5 and in the presence of 500 mu g/mL of LPS. In contrast, LPS did not affect rumen and colon permeability at pH that ranged from 5.5 and 7.4. Translocation of LPS across the rumen and colon mucosa of cattle was not pH dependent. The LPS translocated through these tissues if present at the mucosal side. In conclusion, the permeability of rumen and colon tissues to 3H- mannitol increased in presence of LPS and under acidic pH, whereas LPS permeated through mucosal tissues independently of the pH of the perfusate. Further research is warranted to understand the mechanism(s) by which acidic pH of the rumen digesta and presence of LPS make rumen and colon tissues "leaky".