Guiraldes E, Lamabadusuriya S P, Oyesiku J E, Whitfield T E, Harries J T
Biochim Biophys Acta. 1975 May 21;389(3):495-505. doi: 10.1016/0005-2736(75)90160-1.
The effects of deoxycholate, taurocholate and cholate on transport and mucosal ATPase activity have been investigated in the rat jejunum in vivo using closed-loop and perfusion techniques. In the closed-loops, 5 mM deoxycholate selectively inactivated (Na+ + K+)-ATPase, and net secretion of Na+ induced by 2.5 mM deoxycholate was due to reduced lumen to plasma flux of the ion; deoxycholate (2.5 mM) produced marked inhibition of 3-0-methylglucose transport. Luminal disappearance rates of deoxycholate (60.5 plus or minus 2.9% per g wet st of gut) greatly exceeded those of taurocholate (4.3 plus or minus 1.0). In the perfusion studies 1 mM deoxycholate induced net secretion of water, Na+ and C1-, and inhibited active glucose transport; concomitantly "total" ATPase, (Na+ + K+)-ATPase, and Mg-2+-ATPase were inhibited. At higher concentrations (5 mM) deoxycholate stimulated Mg-2+-ATPase activity. Taurocholate and cholate at 1mM had no effect on transport of (Na+ + K+)-ATPase. Mucosal lactase, sucrase and maltase activities were not affected by 1 mM deoxycholate, taurocholate or cholate. These results suggest that deoxycholate inhibits sodium-coupled glucose transport by inhibition of (Na+ + K+)-ATPase at the lateral and basal membranes of the epithelial cell, rather than from an effect at the brush-border membrane level.
已采用闭环和灌注技术在大鼠空肠体内研究了脱氧胆酸盐、牛磺胆酸盐和胆酸盐对转运及黏膜ATP酶活性的影响。在闭环实验中，5 mM脱氧胆酸盐选择性地使（Na⁺+K⁺）-ATP酶失活，2.5 mM脱氧胆酸盐诱导的Na⁺净分泌是由于该离子从肠腔到血浆的通量减少；2.5 mM脱氧胆酸盐对3-O-甲基葡萄糖转运产生显著抑制。脱氧胆酸盐的肠腔消失率（每克肠湿重60.5±2.9%）大大超过牛磺胆酸盐（4.3±1.0）。在灌注研究中，1 mM脱氧胆酸盐诱导水、Na⁺和Cl⁻的净分泌，并抑制活性葡萄糖转运；同时，“总”ATP酶、（Na⁺+K⁺）-ATP酶和Mg²⁺-ATP酶受到抑制。在较高浓度（5 mM）时，脱氧胆酸盐刺激Mg²⁺-ATP酶活性。1 mM的牛磺胆酸盐和胆酸盐对（Na⁺+K⁺）-ATP酶的转运没有影响。1 mM脱氧胆酸盐、牛磺胆酸盐或胆酸盐对黏膜乳糖酶、蔗糖酶和麦芽糖酶活性没有影响。这些结果表明，脱氧胆酸盐通过抑制上皮细胞侧面和基底膜上的（Na⁺+K⁺）-ATP酶来抑制钠偶联葡萄糖转运，而不是通过对刷状缘膜水平的作用。
