SHORT-CHAIN FATTY-ACIDS STIMULATE ACTIVE SODIUM AND CHLORIDE ABSORPTION INVITRO IN THE RAT DISTAL COLON
SHORT-CHAIN FATTY-ACIDS STIMULATE ACTIVE SODIUM AND CHLORIDE ABSORPTION INVITRO IN THE RAT DISTAL COLON
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DOI：
10.1016/0016-5085(89)91614-4
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发表时间：
1989-04-01
期刊：
影响因子：
29.4
通讯作者：
MEHTA, P
中科院分区：
文献类型：
--
作者：
BINDER, HJ;MEHTA, P
进行了研究，以确定短链脂肪酸增加结肠Na和Cl吸收的机制，通过确定单向22 Na和36 Cl流量从大鼠远端结肠分离剥离粘膜电压钳条件下。粘膜丁酸盐（25 mM，不存在碳酸氢盐）显着增强净钠和净氯吸收7.0 ±-。1.3和6.9 .+-。1.0μ Eq/h. cntdot. cm 2，而不增加短路电流。丁酸盐-林格氏溶液和HCO_3-林格氏溶液中的Na和Cl净吸收相同。丁酸盐刺激钠（和氯）的吸收是Cl-依赖性的，并防止1 mM的粘膜阿米洛利，抑制剂的Na-H交换，但HCO 3的独立性和不抑制乙酰唑胺，碳酸酐酶抑制剂。相反，碳酸氢盐刺激的Na（和Cl）吸收也是Cl依赖性和阿米洛利敏感的，但乙酰唑胺显着抑制。粘膜丁酸盐对净Na和Cl吸收的影响显著大于丁酸丝氨酸，丁酸丝氨酸在碳酸氢盐存在下不会改变离子转运。粘膜丁酸盐对钠和氯吸收的刺激作用显着大于丙酸盐和乙酸盐，而粘膜甲酸盐并不改变钠的转运。本研究的结果允许以下模式：短链脂肪酸刺激活性钠和氯吸收涉及摄取的非离子化形式的丁酸和耦合的Na-H和Cl-丁酸酯交换。
Studies were performed to determine the mechanism by which short-chain fatty acids increase colonic Na and Cl absorption by determining unidirectional 22Na and 36Cl fluxes across isolated stripped mucosa from the rat distal colon under voltage clamp conditions. Mucosal butyrate (25 mM, in the absence of bicarbonate) significantly enhanced both net Na and net Cl absorption by 7.0 .+-. 1.3 and 6.9 .+-. 1.0 .mu.Eq/h .cntdot. cm2, respectively, without increasing the short-circuit current. Net Na and Cl absorption in butyrate-Ringer''s solution and HCO3-Ringer''s solution were identical. Butyrate stimulation of Na (and Cl) absorption was Cl-dependent and prevented by 1 mM mucosal amiloride, an inhibitor of Na-H exchange, but was HCO3-independent and not inhibited by acetazolamide, a carbonic anhydrase inhibitor. In contrast, bicarbonate-stimulated Na (and Cl) absorption was also Cl-dependent and amiloride-sensitive, but was significantly inhibited by acetazolamide. The effect of mucosal butyrate on net Na and Cl absorption was substantially greater than serosal butyrate, which in the presence of bicarbonate did not alter ion transport. The stimulation of Na and Cl absorption by mucosal butyrate was significantly greater than by propionate and acetate, whereas mucosal formate did not alter Na transport. The results of this study permit the following mode: short-chain fatty acid stimulation of active Na and Cl absorption involves uptake of the nonionized form of butyrate and the coupling of Na-H and Cl-butyrate exchanges.