CONTROL OF EPITHELIAL NA+ TRANSPORT BY APICAL NA+ ENTRY
CONTROL OF EPITHELIAL NA+ TRANSPORT BY APICAL NA+ ENTRY
批准号:
2624515
负责人:
JOHN P. JOHNSON
金额:
$12.8万
依托单位国家:
美国
项目类别:
财政年份:
1997
资助国家:
美国
项目状态:
已结题
起止时间:
1997-09-11 至 1998-03-31
中文摘要
在肾上皮细胞中,钠的载体运输是一个两步过程。
英文摘要
In kidney epithelial, vectorial sodium transport is a two step process.
First, sodium entry occurs trough amiloride-blockable ion channels
located in the apical membrane of sodium transporting cells. Second,
the sodium is active transported out of the cells via a basolateral
Na+/K+-ATPase. The net effect of these two processes, which occur
in series, is the vectorial transport of sodium from the luminal
compartment to the basolateral compartment. Previous data suggest
that the rate of apical Na+ entry regulates the activity of these
transporter proteins. Thus, the nA+ reabsorptive capacity of distal
nephron segments increases in response to increased load and
decreases in espouse to decreased load. This form of regulation is
responsible from many clinically important effects on salt balance,
including the maintenance of glomerular-tubular balance, the
phenomenon of diuretic resistance, the development of post-obstructure
diuresis and the occurrence of downstream tubular atrophy in
glomerular disease. Moreover, the control of renal sodium excretion
is involved in the pathogenesis of diverse disease states such as
hypertension, nephrotic syndrome, and congestive heart failure.
Currently, the mechanisms by which the rate of na+ entry regulates
Na+ transporter activity are poorly understood. The proposed studies
will address this issue at a molecular level using a well characterized
model of collecting duct epithelial cells, the A6 cell line grown on
porous supports. Published preliminary data in t his cell culture model
demonstrates that blockage of Na+ entry result in striking on
regulation of both the apical Na+ channel and the basolateral
Na+/K+-ATPase. In addition, stimulation of aplical Na+ etry up-
regulates both pathways. Recently cDNA encoding for three proteins,
alpha, beta, and gamma EnaC (epithelial Na+ channel), has been
identified and cloned. All of the activity of low conductance, highly
sodium selective, amiloride-sensitive epithelial sodium channel from
cortical collecting duct can be accounted for by these channel proteins.
Homologues of these proteins have been described in A6 cells and
have been termed XeNaC (Xenopus Na+ channel). Using antibody
and northern blot probes to the XeNaC channel, and to the alpha and
beta subunits of the Na+/K+-ATPase, the effect of apical Na+ entry
on the transcriptional, translational and post-translational regulation of
these transporter proteins will be described.
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会议论文
Trafficking and Regulation of the Epithelial Na+ Channel
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批准号:7992609
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项目类别:
-
资助金额:$10.0万
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财政年份:2009
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负责人:JOHN P. JOHNSON
-
依托单位:
Trafficking and Regulation of the Epithelial Na+ Channel
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批准号:7545480
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项目类别:
-
资助金额:$23.87万
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财政年份:2002
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负责人:JOHN P. JOHNSON
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依托单位:
Trafficking and Regulation of the Epithelial Na+ Channel
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批准号:8018190
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项目类别:
-
资助金额:$23.39万
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财政年份:2002
-
负责人:JOHN P. JOHNSON
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依托单位:
Trafficking and Regulation of the Epithelial Na+ Channel
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批准号:6844303
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项目类别:
-
资助金额:$24.35万
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财政年份:2002
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负责人:JOHN P. JOHNSON
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依托单位:
Trafficking and Regulation of the Epithelial Na+ Channel
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批准号:7331508
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项目类别:
-
资助金额:$23.87万
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财政年份:2002
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负责人:JOHN P. JOHNSON
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依托单位:
Trafficking and Regulation of the Epithelial Na+ Channel
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批准号:6621217
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项目类别:
-
资助金额:$24.47万
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财政年份:2002
-
负责人:JOHN P. JOHNSON
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依托单位:
Trafficking and Regulation of the Epithelial Na+ Channel
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批准号:6431083
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项目类别:
-
资助金额:$24.55万
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财政年份:2002
-
负责人:JOHN P. JOHNSON
-
依托单位:
Trafficking and Regulation of the Epithelial Na+ Channel
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批准号:7743824
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项目类别:
-
资助金额:$23.63万
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财政年份:2002
-
负责人:JOHN P. JOHNSON
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依托单位:
Trafficking and Regulation of the Epithelial Na+ Channel
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批准号:6703158
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项目类别:
-
资助金额:$24.39万
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财政年份:2002
-
负责人:JOHN P. JOHNSON
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依托单位:
Trafficking and Regulation of the Epithelial Na+ Channel
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批准号:7212758
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项目类别:
-
资助金额:$26.4万
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财政年份:2000
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负责人:JOHN P. JOHNSON
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依托单位:
Cellular Mechanisms of Mineralcorticoid Action
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批准号:6999852
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项目类别:
-
资助金额:$26.75万
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财政年份:1995
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负责人:JOHN P. JOHNSON
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依托单位:
CELLULAR MECHANISMS OF MINERALOCORTICOID ACTION
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批准号:2905617
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项目类别:
-
资助金额:$21.92万
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财政年份:1995
-
负责人:JOHN P. JOHNSON
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依托单位:
Cellular Mechanisms of Mineralcorticoid Action
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批准号:6724563
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项目类别:
-
资助金额:$27.44万
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财政年份:1995
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负责人:JOHN P. JOHNSON
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依托单位:
Cellular Mechanisms of Action of Mineralocorticoid Hormones
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批准号:8288846
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项目类别:
-
资助金额:$31.86万
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财政年份:1995
-
负责人:JOHN P. JOHNSON
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依托单位:
Cellular Mechanisms of Action of Mineralocorticoid Hormones
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批准号:8514578
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项目类别:
-
资助金额:$30.74万
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财政年份:1995
-
负责人:JOHN P. JOHNSON
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依托单位:
CELLULAR MECHANISMS OF MINERALOCORTICOID ACTION
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批准号:2147779
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项目类别:
-
资助金额:$17.16万
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财政年份:1995
-
负责人:JOHN P. JOHNSON
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依托单位:
CELLULAR MECHANISMS OF MINERALOCORTICOID ACTION
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批准号:2414862
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项目类别:
-
资助金额:$16.76万
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财政年份:1995
-
负责人:JOHN P. JOHNSON
-
依托单位:
CELLULAR MECHANISMS OF MINERALOCORTICOID ACTION
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批准号:6177234
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项目类别:
-
资助金额:$22.58万
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财政年份:1995
-
负责人:JOHN P. JOHNSON
-
依托单位:
Cellular Mechanisms of Action of Mineralocorticoid Hormones
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批准号:7727756
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项目类别:
-
资助金额:$35.92万
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财政年份:1995
-
负责人:JOHN P. JOHNSON
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依托单位:
Cellular Mechanisms of Mineralcorticoid Action
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批准号:7169910
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项目类别:
-
资助金额:$25.98万
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财政年份:1995
-
负责人:JOHN P. JOHNSON
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依托单位:
海外基金