Ammonium effects on colonic Cl- secretion: anomalous mole fraction behavior.
Ammonium effects on colonic Cl- secretion: anomalous mole fraction behavior.
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铵对结肠 Cl- 分泌的影响：异常摩尔分数行为。
DOI：
10.1152/ajpgi.00196.2003
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Matthews,JeffreyB
中科院分区：
文献类型：
--
作者：
Worrell,RogerT;Oghene,Jennifer;Matthews,JeffreyB
A significant amount of ammonium (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document}) is absorbed by the colon. The nature of \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} effects on transport and \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} transport itself in colonic epithelium is poorly understood. The goal of this study was to elucidate the effects of \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} on cAMP-stimulated Cl-secretion in the colonic cell line T84. In HEPES-buffered solutions, application of basolateral \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} resulted in a reduced level of Cl-secretory current. The effect of \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} appears to occur by at least three mechanisms:1) basolateral membrane depolarization,2) a competitive effect with K+, and3) a long-term (>20 min) increase in transepithelial resistance (TER). The competitive effect with K+exhibits anomalous mole fraction behavior. Transepithelial current relative to that in 10 mM basolateral K+was inhibited 15% by 10 mM \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} alone and by 30% with a mixture of 2 mM K+and 8 mM \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document}. A mole fraction mix of 2 mM K+:8 mM \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} produced a greater inhibition of basolateral membrane K+current than pure K+or \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} alone. Similar anomalous behavior was also observed for inhibition of bumetanide-sensitive36Cl-uptake, e.g., Na+-K+-2Cl--cotransporter (NKCC-1). No anomalous effect was observed on Na+-K+-ATPase current. Both NKCC-1 and Na+-K+-ATPase activity were elevated in 10 mM \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} with respect to 10 mM K+. The effect on TER did not exhibit anomalous mole fraction behavior. The overall effect of basolateral \batchmode \documentclass[fleqn,10pt,legalpaper]{article …
A significant amount of ammonium (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document}) is absorbed by the colon. The nature of \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} effects on transport and \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} transport itself in colonic epithelium is poorly understood. The goal of this study was to elucidate the effects of \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} on cAMP-stimulated Cl-secretion in the colonic cell line T84. In HEPES-buffered solutions, application of basolateral \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} resulted in a reduced level of Cl-secretory current. The effect of \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} appears to occur by at least three mechanisms:1) basolateral membrane depolarization,2) a competitive effect with K+, and3) a long-term (>20 min) increase in transepithelial resistance (TER). The competitive effect with K+exhibits anomalous mole fraction behavior. Transepithelial current relative to that in 10 mM basolateral K+was inhibited 15% by 10 mM \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} alone and by 30% with a mixture of 2 mM K+and 8 mM \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document}. A mole fraction mix of 2 mM K+:8 mM \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} produced a greater inhibition of basolateral membrane K+current than pure K+or \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} alone. Similar anomalous behavior was also observed for inhibition of bumetanide-sensitive36Cl-uptake, e.g., Na+-K+-2Cl--cotransporter (NKCC-1). No anomalous effect was observed on Na+-K+-ATPase current. Both NKCC-1 and Na+-K+-ATPase activity were elevated in 10 mM \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} with respect to 10 mM K+. The effect on TER did not exhibit anomalous mole fraction behavior. The overall effect of basolateral \batchmode \documentclass[fleqn,10pt,legalpaper]{article …