Glutamine transporter in crypts compensates for loss of villus absorption in bovine cryptosporidiosis
Glutamine transporter in crypts compensates for loss of villus absorption in bovine cryptosporidiosis
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DOI：
10.1152/ajpgi.2001.281.3.g645
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发表时间：
2001-09-01
影响因子：
4.5
通讯作者：
Argenzio, R
中科院分区：
文献类型：
--
作者：
Blikslager, A;Hunt, E;Argenzio, R
小隐孢子虫感染是人类和动物腹泻的重要原因。在Ussing实验室内研究了光照作用谷氨酰胺和PG合成抑制剂吲哚美辛对感染犊牛回肠NaCl吸收的影响。感染回肠黏膜表面积和NaCl吸收均下降。吲哚美辛和谷氨酰胺或其稳定的衍生物丙氨酰谷氨酰胺以添加剂的方式增加了感染组织中Na+的净吸收，并且比对照组的吸收程度更大。免疫组织化学和Western blot研究表明，在对照动物中，中性氨基酸运输系统ABC存在于绒毛和隐窝中，而在感染动物中，ASC仅强烈存在于隐窝的顶端边界。这些结果与PGs介导了侵染过程中NaCl和水分吸收的改变相一致。我们的研究结果进一步表明，尽管绒毛严重萎缩，但PG合成抑制剂和谷氨酰胺的联合使用可以充分刺激Na+和Cl-的吸收，这种效果与感染隐窝中Na+依赖性氨基酸转运蛋白的表达增加有关。
Cryptosporidium parvum infection represents a significant cause of diarrhea in humans and animals. We studied the effect of luminally applied glutamine and the PG synthesis inhibitor indomethacin on NaCl absorption from infected calf ileum in Ussing chambers. Infected ileum displayed a decrease in both mucosal surface area and NaCl absorption. Indomethacin and glutamine or its stable derivative alanyl-glutamine increased the net absorption of Na+ in infected tissue in an additive manner and to a greater degree than in controls. Immunohistochemical and Western blot studies showed that in control animals neutral amino acid transport system ABC was present in villus and crypts, whereas in infected animals, ASC was strongly present only on the apical border of crypts. These results are consistent with PGs mediating the altered NaCl and water absorption in this infection. Our findings further illustrate that the combined use of a PG synthesis inhibitor and glutamine can fully stimulate Na+ and Cl- absorption despite the severe villous atrophy, an effect associated with increased expression of a Na+-dependent amino acid transporter in infected crypts.