Diet and carcinogen alter luminal butyrate concentration and intracellular pH in isolated rat colonocytes.
Diet and carcinogen alter luminal butyrate concentration and intracellular pH in isolated rat colonocytes.
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饮食和致癌物质改变离体大鼠结肠细胞中的管腔丁酸盐浓度和细胞内 pH 值。
DOI：
10.1080/01635589709514530
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Lupton,JR
中科院分区：
文献类型：
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作者：
Zoran,DL;Barhoumi,R;Burghardt,RC;Chapkin,RS;Lupton,JR
采用2 × 2析因实验研究了两种不同膳食纤维和致癌物处理对大鼠结肠腔短链脂肪酸（SCFA）浓度和细胞内pH（pHi）的影响。将24只雄性Sprague-道利大鼠分为4组，注射致癌物[氧化偶氮甲烷（AOM）]或生理盐水（Sal），并喂食仅在膳食纤维类型[纤维素（Cell）或果胶（Pect）]方面不同的两种饲料之一。在食用这些饮食38周后，对大鼠实施安乐死，收集管腔内容物用于分析SCFA浓度，并且从近端和远端结肠分离结肠细胞用于随后测定pH。还测试了向培养基中添加外源性丁酸钠后pH的变化。消耗果胶饮食的对照大鼠（注射盐水）产生最高浓度的SCF As。与生理盐水对照组相比，致癌物注射组的四个结肠段中的三个结肠段[近端和远端纤维素（近端细胞和远端细胞）和远端果胶（远端果胶）]的管腔丁酸盐浓度降低。从注射致癌物的大鼠中分离的结肠细胞的pH值始终高于注射生理盐水的大鼠细胞（近端细胞/AOM = 6.95 vs.近端细胞/Sal = 6.65，近端Pect/AOM = 6.75 vs.近端Pect/Sal = 6.65，远端细胞/AOM = 6.94 vs.远端细胞/AOM = 6.85，远端Pect/AOM = 6.92 vs.远端Pect/Sal = 6.79）。此外，在大多数大鼠中，近端结肠的pH值低于远端结肠。向培养的结肠细胞中添加丁酸盐始终降低pHi，但在注射致癌物的动物中效果更明显。这些数据确定的变化，发生在肠腔内和细胞内注射AOM的大鼠结肠，并表明，在肿瘤发生过程中，丁酸盐的生产和基本的结肠细胞生理学的改变可能在这个过程中发挥重要作用。
A 2 × 2 factorial experiment was conducted to examine the effects of two different dietary fibers and carcinogen treatment on colonic luminal short‐chain fatty acid (SCFA) concentrations and intracellular pH (pHi) in rats. Twenty‐four male Sprague‐Dawley rats were divided into four groups, injected with a carcinogen [azoxymethane (AOM)] or normal saline (Sal), and fed one of two diets differing only in the type of dietary fiber [cellulose (Cell) or pectin (Pect)]. After 38 weeks of consuming these diets, the rats were euthanized, luminal contents were collected for analysis of SCFA concentrations, and colonocytes were isolated from the proximal and distal colon for subsequent determination of pHiChanges in pHiafter the addition of exogenous sodium butyrate to the culture medium were also tested. The highest concentrations of SCF As were produced by the control rats (saline injected) consuming the pectin diet. Luminal butyrate concentrations were reduced in three of four colonic segments of carcinogen‐injected groups [proximal and distal cellulose (Prox Cell and Dist Cell) and distal pectin (Dist Pect)] compared with saline controls. The pHiwas consistently higher in colonocytes isolated from carcinogen‐injected rats (Prox Cell/AOM = 6.95 vs. Prox Cell/Sal = 6.65, Prox Pect/AOM = 6.75 vs. Prox Pect/Sal = 6.65, Dist Cell/AOM = 6.94 vs. Dist Cell/AOM = 6.85, Dist Pect/AOM = 6.92 vs. Dist Pect/Sal = 6.79) than in cells from saline‐injected rats. Furthermore, in the majority of rats, pHiwas lower in the proximal than in the distal colon. Addition of butyrate to cultured colonocytes consistently lowered pHi, but the effect was more pronounced in the carcinogen‐injected animals. These data identify changes that occur intraluminally and intracellularly in colons of rats injected with AOM and suggest that, during tumorigenesis, alterations in butyrate production and basic colonocyte physiology may play an important role in the process.