Referenced in: none

Automatically associated channels: SK1 , SK3

Title: Task3 Potassium Channel Gene Invalidation Causes Low Renin and Salt-Sensitive Arterial Hypertension.

Authors: David Penton, Sascha Bandulik, Frank Schweda, Sophia Haubs, Philipp Tauber, Markus Reichold, Lu Dang Cong, Abeer El Wakil, Thomas Budde, Florian Lesage, Enzo Lalli, Maria-Christina Zennaro, Richard Warth, Jacques Barhanin

Journal, date & volume: Endocrinology, 2012 Aug 9 , ,

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22878402

Abstract
Task1 and Task3 potassium channels (Task: tandem of P domains in a weak inward rectifying K(+) channel-related acid-sensitive K(+) channel) are believed to control the membrane voltage of aldosterone-producing adrenal glomerulosa cells. This study aimed at understanding the role of Task3 for the control of aldosterone secretion. The adrenal phenotype of Task3(-/-) mice was investigated using electrophysiology, adrenal slices, and blood pressure measurements. Primary adrenocortical cells of Task3(-/-) mice were strongly depolarized compared with wild-type (-52 vs. -79 mV), and in fresh adrenal slices Ca(2+) signaling of Task3(-/-) glomerulosa cells was abnormal. In living Task3(-/-) mice, the regulation of aldosterone secretion showed specific deficits: Under low Na(+) and high K(+) diets, protocols known to increase aldosterone, and under standard diet, Task3 inactivation was compensated and aldosterone was normal. However, high Na(+) and low K(+) diets, two protocols known to lower aldosterone, failed to lower aldosterone in Task3(-/-) mice. The physiological regulation of aldosterone was disturbed: aldosterone-renin ratio, an indicator of autonomous aldosterone secretion, was 3-fold elevated at standard and high Na(+) diets. Isolated adrenal glands of Task3(-/-) produced 2-fold more aldosterone. As a consequence, Task3(-/-) mice showed salt-sensitive arterial hypertension (plus 10 mm Hg). In conclusion, Task3 plays an important role in the adaptation of aldosterone secretion to dietary salt intake.