What question did this study set out to answer?

To characterize the single-channel properties and regulatory mechanisms of potassium channels in the apical membrane of rat cortical collecting tubules.

September 1, 1990AJP Renal Physiology

Regulation of small-conductance K+ channel in apical membrane of rat cortical collecting tubule

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Authors

WWW. H. Wang ASA. Schwab GGGerhard Giebisch

Discussion

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Overview

Patch-clamp study demonstrates metabolic and pH regulation of apical potassium channels in rat renal tubules, indicating their central role in potassium secretion.

Key Points

To characterize the single-channel properties and regulatory mechanisms of potassium channels in the apical membrane of rat cortical collecting tubules.
Performed patch-clamp recordings (cell-attached and inside-out configurations) on isolated cortical collecting tubules from rat kidneys at 37°C.
Evaluated channel conductance, open probability, ion selectivity, and responses to barium, tetraethylammonium, dietary potassium intake, intracellular pH changes, and ATP/ADP exposure.
Single-channel inward conductance was 35 pS (n = 106) and outward conductance was 15 pS (n = 15), exhibiting a high voltage-independent open probability of 0.96 and a 20:1 potassium-to-sodium selectivity ratio.
A high-potassium diet increased channel incidence from 32% (53 of 165 patches) in controls to 64% (53 of 83 patches).
Channel activity was reversibly inhibited by lowering cytoplasmic pH from 7.4 to 6.9 (open probability dropped from 0.9 to 0.1) and by 1 mM ATP, with ATP inhibition relieved by 0.5 mM ADP.

Cite This Study

Wang et al. (1990) studied this question.

synapsesocial.com/papers/6a7ea6df4fe759ebdc8ec2c6 https://doi.org/10.1152/ajprenal.1990.259.3.f494

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September 1, 1990AJP Renal Physiology

Regulation of small-conductance K+ channel in apical membrane of rat cortical collecting tubule

View Full Paper

Ask AI

Bookmark

Authors

WWW. H. Wang ASA. Schwab GGGerhard Giebisch

Discussion

Member takes

Overview

Patch-clamp study demonstrates metabolic and pH regulation of apical potassium channels in rat renal tubules, indicating their central role in potassium secretion.

Key Points

To characterize the single-channel properties and regulatory mechanisms of potassium channels in the apical membrane of rat cortical collecting tubules.
Performed patch-clamp recordings (cell-attached and inside-out configurations) on isolated cortical collecting tubules from rat kidneys at 37°C.
Evaluated channel conductance, open probability, ion selectivity, and responses to barium, tetraethylammonium, dietary potassium intake, intracellular pH changes, and ATP/ADP exposure.
Single-channel inward conductance was 35 pS (n = 106) and outward conductance was 15 pS (n = 15), exhibiting a high voltage-independent open probability of 0.96 and a 20:1 potassium-to-sodium selectivity ratio.
A high-potassium diet increased channel incidence from 32% (53 of 165 patches) in controls to 64% (53 of 83 patches).
Channel activity was reversibly inhibited by lowering cytoplasmic pH from 7.4 to 6.9 (open probability dropped from 0.9 to 0.1) and by 1 mM ATP, with ATP inhibition relieved by 0.5 mM ADP.

Cite This Study

Wang et al. (1990) studied this question.

synapsesocial.com/papers/6a7ea6df4fe759ebdc8ec2c6 https://doi.org/10.1152/ajprenal.1990.259.3.f494

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