Corticosteroid alteration of active electrolyte transport in rat distal colon.
Corticosteroid alteration of active electrolyte transport in rat distal colon.
复制标题
皮质类固醇对大鼠远端结肠主动电解质转运的改变。
DOI：
10.1152/ajpgi.1983.245.5.g668
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Binder,HJ
中科院分区：
文献类型：
--
作者：
Foster,ES;Zimmerman,TW;Hayslett,JP;Binder,HJ
为了确定皮质类固醇对主动转运过程的影响，在短路条件下测量了22Na、36Cl和42K在分离的大鼠、对照组、继发高醛固酮组和地塞米松组的结肠远端粘膜的单向通量。在对照组中，净钠和氯通量（JNanet和JClnet）和短路电流（Isc）分别为6.6 +/- 2.2、7.6 +/- 1.6和1.3 +/- 0.2 μ eq X h-1 X cm-2。虽然醛固酮使Isc升高至7.3 +/- 0.5 μ eq X h-1 X cm-2，但JNanet （6.9 +/- 0.7 μ eq X h-1 X cm-2）未发生变化，JClnet降至0。地塞米松也刺激Isc，但不抑制JClnet。在无cl的林格格组中，醛固酮和地塞米松均能显著增加JNanet和Isc。茶碱在对照动物中消除了JNanet，而醛固酮组没有。醛固酮将净钾吸收（0.58 +/- 0.11 μ eq X h-1 X cm-2）与净钾分泌（-0.94 +/- 0.08 μ eq X h-1 X cm-2）逆转。地塞米松使净钾迁移量降至0 （-0.04 +/- 0.12 mu eq X h-1 X cm-2）。这些研究表明：1)皮质类固醇刺激电致钠吸收；2)醛固酮抑制中性NaCl吸收，刺激活性钾分泌，而地塞米松没有作用。矿皮质激素和糖皮质激素对电解质转运的影响是不相同的，可能是由不同的机制介导的。
To determine the effect of corticosteroids on active transport processes, unidirectional fluxes of 22Na, 36Cl, and 42K were measured under short-circuit conditions across isolated stripped distal colonic mucosa of the rat in control, secondary hyperaldosterone, and dexamethasone-treated animals. In controls net sodium and chloride fluxes (JNanet and JClnet) and short-circuit current (Isc) were 6.6 +/- 2.2, 7.6 +/- 1.6, and 1.3 +/- 0.2 mu eq X h-1 X cm-2, respectively. Although aldosterone increased Isc to 7.3 +/- 0.5 mu eq X h-1 X cm-2, JNanet (6.9 +/- 0.7 mu eq X h-1 X cm-2) was not altered and JClnet was reduced to 0 compared with controls. Dexamethasone also stimulated Isc but did not inhibit JClnet. In Cl-free Ringer both aldosterone and dexamethasone produced significant and equal increases in JNanet and Isc. Theophylline abolished JNanet in control animals but not in the aldosterone group. Aldosterone reversed net potassium absorption (0.58 +/- 0.11 mu eq X h-1 X cm-2) to net potassium secretion (-0.94 +/- 0.08 mu eq X h-1 X cm-2). Dexamethasone reduced net potassium movement to 0 (-0.04 +/- 0.12 mu eq X h-1 X cm-2). These studies demonstrate that 1) corticosteroids stimulate electrogenic sodium absorption and 2) aldosterone, but not dexamethasone, inhibits neutral NaCl absorption and stimulates active potassium secretion. The effects of mineralocorticoids and glucocorticoids on electrolyte transport are not identical and may be mediated by separate and distinct mechanisms.