Cl<sup>‐</sup> Conductance and Acid Secretion in the Human Sweat Duct

Quinton, Paul M.; Reddy, M. M.

doi:10.1111/j.1749-6632.1989.tb25182.x

Cited by 39 publications

(28 citation statements)

References 8 publications

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Section: Absence Of K + Conductance In the Apmmentioning

confidence: 55%

“…Imposition of a K + gradient by K + substitution in the lumen did not have any effect on the [K+]i or on the electrical properties of the RSD [23]. Further, application of Ba 2+ in the lumen did not affect [K+]i [23]. By comparison, both of these manipulations in the bath had a significant effect on the BLM potential (Tables 3 and 5 Table 3) also suggesting that Va is insensitive to changes in [K+]~ due to the absence of K § conductance in the APM.…”

Section: Absence Of K + Conductance In the Apmmentioning

confidence: 69%

“…Although some of the loss of K + can be attributed to passive efflux of K + due to slightly increased driving force (AE k) due to removal of extracellular K + , inhibition of Na+/K + pump is probably the main cause of depletion of [K+]; [1]. Upon reactivation of the pump by introducing K + into the bath, there was a rapid hyperpolarization of BLM with a significant undershoot of Vb [23] which is consistent with the activation of Na+/K + pump activity as was observed in the proximal tubule [1]. A comparison of the apparent rate of decrease of [K+]i during inhibition of Na +/K + pump activity with the apparent rate of K + uptake during the activation of the pump as reflected by changes in [K+]; reveals that the rate of efflux of K + due to K + removal from the bath is about four times slower than the rate of active uptake of K + due to the reintroduction of K + into the medium [23] which is compatible with rapid activation of the Na+/K + pump activity in the BLM.…”

Section: Effect Of C1-on [K+]imentioning

confidence: 97%

“…Upon reactivation of the pump by introducing K + into the bath, there was a rapid hyperpolarization of BLM with a significant undershoot of Vb [23] which is consistent with the activation of Na+/K + pump activity as was observed in the proximal tubule [1]. A comparison of the apparent rate of decrease of [K+]i during inhibition of Na +/K + pump activity with the apparent rate of K + uptake during the activation of the pump as reflected by changes in [K+]; reveals that the rate of efflux of K + due to K + removal from the bath is about four times slower than the rate of active uptake of K + due to the reintroduction of K + into the medium [23] which is compatible with rapid activation of the Na+/K + pump activity in the BLM. Part of the differences in the kinetics of [K+]i during inhibition and reactivation of the Na +/K + pump could be due to cell swelling (during inhibition of the Na+/K + pump) and shrinking (during reactivation of the Na+/K + pump).…”

Section: Effect Of C1-on [K+]imentioning

confidence: 99%

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Intracellular potassium activity and the role of potassium in transepithelial salt transport in the human reabsorptive sweat duct

Reddy

Quinton

1991

J. Membrain Biol.

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We have measured the intracellular potassium activity, [K+]i and the mechanisms of transcellular K+ transport in reabsorptive sweat duct (RSD) using intracellular ion-sensitive microelectrodes (ISMEs). The mean value of [K+]i in RSD is 79.8 +/- 4.1 mM (n = 39). Under conditions of microperfusion, the [K+]i is above equilibrium across both the basolateral membrane, BLM (5.5 times) and the apical membrane, APM (7.8 times). The Na+/K+ pump inhibitor ouabain reduced [K+]i is insensitive to the Na+/K+/2 Cl- cotransport inhibitor bumetanide in the bath. Cl- substitution in the lumen had no effect on [K+]i. In contrast, Cl- substitution in the bath (basolateral side) depolarized BLM from -26.0 +/- 2.6 mV to -4.7* +/- 2.4 mV (n = 3; *indicates significant difference) and decreased [K+]i from 76.0 +/- 15.2 mM to 57.7* +/- 12.7 mM (n = 3). Removal of K+ in the bath decreased [K+]i from 76.3 +/- 15.0 mM to 32.3 +/- 7.6 mM (n = 4) while depolarizing the BLM from -32.5 +/- 4.1 mV to -28.3* +/- 3.0 mV (n = 4). Raising the [K+] in the bath by 10-fold increased [K+]i from 81.7 +/- 9.0 mM to 95.0* +/- 13.5 mM and depolarized the BLM from -25.7 +/- 2.4 mV to -21.3* +/- 2.9 mV (n = 4). The K+ conductance inhibitor, Ba2+, in the bath also increased [K+]i from 85.8 +/- 6.7 mM to 107.0* +/- 11.5 mM (n = 4) and depolarized BLM from -25.8 +/- 2.2 mV to -17.0* +/- 3.1 mV (n = 4). Amiloride at 10(-6) M increased [K+]i from 77.5 +/- 18.8 mM to 98.8* +/- 21.6 mM (n = 4) and hyperpolarized both the BLM (from -27.5 +/- 1.4 mV to -46.0* +/- 3.5 mV, n = 4). However, amiloride at 10(-4) M decreased [K+]i from 64.5 +/- 0.9 mM to 36.0* +/- 9.9 mM and hyperpolarized both the BLM (from -24.7 +/- 1.4 mV to -43.5* +/- 4.2 mV) and APM (from -18.3 +/- 0.9 mV to -43.5* +/- 4.2 mV, n = 6). In contrast to the observations at the BLM, substitution of K+ or application of Ba2+ in the lumen had no effect on the [K+]i or the electrical properties of RSD, indicating the absence of a K+ conductance in the APM.(ABSTRACT TRUNCATED AT 400 WORDS)

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Section: Absence Of K + Conductance In the Apmmentioning

confidence: 55%

Section: Absence Of K + Conductance In the Apmmentioning

confidence: 69%

Section: Effect Of C1-on [K+]imentioning

confidence: 97%

Section: Effect Of C1-on [K+]imentioning

confidence: 99%

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Intracellular potassium activity and the role of potassium in transepithelial salt transport in the human reabsorptive sweat duct

Reddy

Quinton

1991

J. Membrain Biol.

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“…8 A) and an ensemble average (Fig. 8 B) (8,20), in whole cell patch-clamp studies of T84 cells (21), in sweat gland duct cells (22), and in two different cell types using two different expression systems (8).…”

Section: Methodsmentioning

confidence: 99%

Identification and regulation of the cystic fibrosis transmembrane conductance regulator-generated chloride channel.

Berger¹,

Anderson²,

Gregory³

et al. 1991

J. Clin. Invest.

237

108

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Cystic fibrosis tnsmembrane conductance regulator (CFTR) generates cAMP-regulated channels; mutations in CFFR cause defective Cl-channel function in cystic fibrosis epithelia. We used the patch-chmp technique to determine the single channel properties of Cl-channels in cells expressing recombinant CFIR. In cell-attached patches, an increase in cellular cAMP reversibly activated low conductance Cl-channels. cAMP-dependent regulation is due to phosphorylation, because the catalytic subunit of cAMP-dependent protein kinase plus ATP reversibly activated the channel in excised, cell-free patches of membrane. In symmetrical a-solutions, the channel had a channel conductance of 10.4±0.2 (a = 7) pS and a linear current-voltage relation. The channel was more permeable to Cla than to I-and showed no appreciable time-dependent voltage effects. These biophysical properties are consistent with macroscopic studies of a-channels in single cells expressing CFTR and in the apical membrane of secretory epithelia. Identification of the single channel characteristics of CFIR-generated channels allows further studies oftheir regulation and the mechanism of ion permeation. (J. Cli,. Invest.

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The AC conductivity of human sweat ducts as the dominant factor in the sub‐THz reflection coefficient of skin

Betzalel

Ishai

Einav

et al. 2021

Journal of Biophotonics

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The helical nature of human sweat ducts, combined with the morphological and dielectric properties of skin, suggests electromagnetic activity in the sub-THz frequency band. A detailed electromagnetic simulation model of the skin, with embedded sweat ducts, was created. The model includes realistic dielectric properties based on the measured water content of each layer of skin, derived from Raman Spectroscopy. The model was verified by comparing it to measurements of the reflection coefficient of the palms of 13 volunteers in the frequency band 350-410 GHz. They were subjected to a measurement protocol intended to induce mental stress, thereby also activating the sweat glands. The Galvanic Skin Response was concurrently measured. Using the simulation model the optimal ac-conductivity for each measurement was found. The range of variation for all subjects was found to be from 100 S/m to a maximum value of 6000 S/m with averages of 1000 S/m. These are one order of magnitude increase from the accepted values for water at these frequencies (~100 s/m at 100 GHz). Considering the known biochemical mechanism for inducing perspiration, we conclude that these ac-conductivity levels are probably valid, even though the real time measurements of sweat ac-conductivity levels inside the duct are inaccessible.

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Cl^‐ Conductance and Acid Secretion in the Human Sweat Duct

Cited by 39 publications

References 8 publications

Intracellular potassium activity and the role of potassium in transepithelial salt transport in the human reabsorptive sweat duct

Intracellular potassium activity and the role of potassium in transepithelial salt transport in the human reabsorptive sweat duct

Identification and regulation of the cystic fibrosis transmembrane conductance regulator-generated chloride channel.

The AC conductivity of human sweat ducts as the dominant factor in the sub‐THz reflection coefficient of skin

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Cl‐ Conductance and Acid Secretion in the Human Sweat Duct

Cited by 39 publications

References 8 publications

Intracellular potassium activity and the role of potassium in transepithelial salt transport in the human reabsorptive sweat duct

Intracellular potassium activity and the role of potassium in transepithelial salt transport in the human reabsorptive sweat duct

Identification and regulation of the cystic fibrosis transmembrane conductance regulator-generated chloride channel.

The AC conductivity of human sweat ducts as the dominant factor in the sub‐THz reflection coefficient of skin

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Product

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Cl^‐ Conductance and Acid Secretion in the Human Sweat Duct