Aldosterone‐Controlled Linkage between Na
 +
 /H
 +
 Exchange and K
 +
 Channels in Fused Renal Epithelial Cells

Oberleithner, Hans; Kersting, U.; Gaßner, Birgit

doi:10.1002/9780470513699.ch12

Cited by 3 publications

(1 citation statement)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the case of swirling flows, the bias in the direction of swirl has a great influence on hydrodynamic stability by biasing the strength of co-rotating and counter-rotating helical modes [27][28][29][30][31]. For example, stability calculations were performed by Loiseleux et al [27], for a Rankine vortex model with the following velocity profiles:…”

Section: Introductionmentioning

confidence: 99%

Premixed flame response to helical disturbances: Mean flame non-axisymmetry effects

Acharya

Lieuwen

2016

Combustion and Flame

View full text Add to dashboard Cite

A key component of the thermoacoustic instability feedback mechanism is the excitation of hydrodynamic flow disturbances by narrowband acoustic fluctuations. In earlier work, we considered the response of time-averaged axisymmetric flames to helical disturbances. That study showed that although all helical modes cause local flame wrinkling, only the axisymmetric hydrodynamic mode, m = 0, contributes to the global heat release rate fluctuations. This paper extends this work to consider time-averaged flames that are non-axisymmetric. We show that distortions of the unforced flame shape changes its receptivity to helical disturbances, as it does not allow for the perfect destructive interference seen in axisymmetric flames. This results in a non-zero global flame response contribution from helical modes. Given that helical modes often have the largest amplitudes in jet flows, particularly those with swirl, these results show that the degree of non axisymmetry of the flame has an important influence in determining which hydrodynamic modes, axisymmetric or helical, control the global heat release response of the flame. These points have been illustrated with example calculations that show how different control parameters and the degree of time-averaged non-axisymmetry influence the global flame response. An important implication of these results relates to scaling results from simplified geometries where a round jet is placed inside a round enclosure, to more realistic ones (such as where multiple jets are placed next to each other) where the flame shape will be distorted from being perfectly circular.

show abstract

Section: Introductionmentioning

confidence: 99%

Premixed flame response to helical disturbances: Mean flame non-axisymmetry effects

Acharya

Lieuwen

2016

Combustion and Flame

View full text Add to dashboard Cite

show abstract

Rapid Effects of Aldosterone on Sodium-Hydrogen Exchange in Isolated Colonic Crypts

et al. 1999

Journal of Membrane Biology

View full text Add to dashboard Cite

Aldosterone plays a central role in the homeostatic regulation of extracellular fluid volume by stimulating transepithelial electrolyte transport. These effects involve binding to an intracellular receptor, modification of genomic events and protein synthesis. Rapid cellular responses to steroid hormones have been observed in a variety of nonepithelial tissues. The term "nongenomic" has been proposed for these fast steroid responses since they are unaffected by inhibitors of protein synthesis. We hypothesized that colonic crypts, recently demonstrated to absorb fluid, would respond rapidly to aldosterone. Cytoplasmic pH changes in crypts loaded with a pH-sensitive, fluorescent dye (BCECF) were recorded with confocal laser imaging. An intracellular alkalization of colonic crypts was observed within one minute of aldosterone application that was inhibited by ethylisopropylamiloride or the absence of extracellular sodium, yet unaffected by inhibitors of protein synthesis. The genesis of this rapid and distinct steroid action involves a signal transduction pathway that involves G proteins, protein kinase C, and prostaglandins. We have identified, by real-time imaging, a nongenomic upregulation of sodium-hydrogen exchange in colonic crypts by aldosterone that occurs independent of the traditional receptor. This distinct, rapid onset effect of aldosterone on epithelial ion transport has major implications for our understanding of fluid and electrolyte homeostasis in health and disease.

show abstract

Rapid activation of KATP channels by aldosterone in principal cells of frog skin.

Urbach

Kerkhove

Maguire

et al. 1996

The Journal of Physiology

View full text Add to dashboard Cite

1. In epithelial cells of frog skin, potassium ions are recycled across the basolateral membrane via an inward-rectifier, ATP-sensitive K+ channel (KATP channel). In this study, we show that aldosterone has a stimulatory effect on KATP channel activity and we have investigated the involvement of Na+-H+ exchange and intracellular pH (pHi) in this phenomenon.2. Aldosterone (10 nM) produced an increase in the open probability of the KATP channel within 15 min from 0-21 + 0 05 to 0 93 + 0.10 (n = 8), measured in cell-attached patches. Aldosterone also increased the tolbutamide-sensitive K+ current across the basolateral membrane within 30 min from 17-2 + 1P9 to 30 3 + 1-6 1A cm2 (n = 8) in nystatinpermeabilized whole skins.3. The KATP channel is very sensitive to variations in cytosolic pH within the physiological range 7 0-7 4.4. The intracellular pH of principal cells is regulated by Na+-H+ exchange, and the stimulatory effect of aldosterone on KATP channel activity was abolished by amiloride (100 uM) added on the basolateral side of the epithelium either before or after aldosterone treatment.5. We propose that aldosterone activates the KATP channels via stimulation of Na+-H+ exchange. The rapidity of aldosterone activation of KATP channels is presented as evidence for a novel non-genomic steroid hormone effect on epithelial ion transport.

show abstract

Aldosterone‐Controlled Linkage between Na ⁺ /H ⁺ Exchange and K ⁺ Channels in Fused Renal Epithelial Cells

Cited by 3 publications

References 19 publications

Premixed flame response to helical disturbances: Mean flame non-axisymmetry effects

Premixed flame response to helical disturbances: Mean flame non-axisymmetry effects

Rapid Effects of Aldosterone on Sodium-Hydrogen Exchange in Isolated Colonic Crypts

Rapid activation of KATP channels by aldosterone in principal cells of frog skin.

Contact Info

Product

Resources

About

Aldosterone‐Controlled Linkage between Na + /H + Exchange and K + Channels in Fused Renal Epithelial Cells

Cited by 3 publications

References 19 publications

Premixed flame response to helical disturbances: Mean flame non-axisymmetry effects

Premixed flame response to helical disturbances: Mean flame non-axisymmetry effects

Rapid Effects of Aldosterone on Sodium-Hydrogen Exchange in Isolated Colonic Crypts

Rapid activation of KATP channels by aldosterone in principal cells of frog skin.

Contact Info

Product

Resources

About

Aldosterone‐Controlled Linkage between Na ⁺ /H ⁺ Exchange and K ⁺ Channels in Fused Renal Epithelial Cells