Studies of Ph of Sweat Produced by Different Forms of Stimulation*

Herrmann, F.; Mandol, Leona

doi:10.1038/jid.1955.36

Cited by 41 publications

(21 citation statements)

References 26 publications

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“…To characterize the operational stability of PB, continuous CV scanning (Figure e) was first conducted at pH = 5, 7, and 8.5 (spanning across the physiological relevant range of sweat pH) . As shown in Figure e, at pH = 5, the cathodic peak currents of the PB redox reaction decreased linearly over the course of the CV recordings.…”

Section: Resultsmentioning

confidence: 99%

A Mediator‐Free Electroenzymatic Sensing Methodology to Mitigate Ionic and Electroactive Interferents' Effects for Reliable Wearable Metabolite and Nutrient Monitoring

Cheng

Wang

Zhao

et al. 2019

Adv Funct Materials

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Wearable electroenzymatic sensors enable monitoring of clinically informative biomolecules in epidermally retrievable biofluids. Conventional wearable enzymatic sensors utilize Prussian Blue (a redox mediator) to achieve selectivity against electroactive interferents. However, the use of Prussian Blue presents fundamental challenges including: 1) the susceptibility of the sensor response to dynamic concentration variation of ionic species and 2) the poor operational stability due to the degradation of its framework. As an alternative wearable electroenzymatic sensor development methodology to bypass the aforementioned limitations, a mediator‐free sensing interface is devised, comprising of a coupled platinum nanoparticle/multiwall carbon nanotube layer and a permselective membrane. The interface is adapted to develop sensors targeting glucose, lactate, and choline (as examples of informative metabolites and nutrients), showing high degrees of sensitivity, selectivity (against a wide panel of naturally present and diverse interfering species), stability (<6.5% signal drift over 20 h operation), and reliability of sensing operation in sweat samples. By integration within a readout board, a wireless sample‐to‐answer system is realized for on‐body sweat biomarker analysis. This methodology can be adapted to target a wide panel of biomarkers in various biofluids, introducing a new sensor development direction for personal health monitoring.

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Section: Resultsmentioning

confidence: 99%

A Mediator‐Free Electroenzymatic Sensing Methodology to Mitigate Ionic and Electroactive Interferents' Effects for Reliable Wearable Metabolite and Nutrient Monitoring

Cheng

Wang

Zhao

et al. 2019

Adv Funct Materials

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“…There are, however, a few mammalian acidic physiological conditions where pH gets close to this value. For instance, sweat shows acidic pH levels, between 4.6 and 5.4 [56], and in the skin the protective sweat acid mantle acidity ranges from 4 to 5.5 [56]; the pH of human stomach is highly acidic, usually from 1 to 2; osteoclasts’ acidic microenvironment below pH 5.5 is critical for the bone resorption [57]; an acidic pH luminal fluid microenvironment is important for sperm maturation [58]. Interestingly, AQP5 was found expressed in sweat glands [59], gastric mucosa [60], bone cells [61], and in the epididymis [58].…”

Section: Discussionmentioning

confidence: 99%

Rat Aquaporin-5 Is pH-Gated Induced by Phosphorylation and Is Implicated in Oxidative Stress

Rodrigues

Mósca

Martins

et al. 2016

IJMS

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Aquaporin-5 (AQP5) is a membrane water channel widely distributed in human tissues that was found up-regulated in different tumors and considered implicated in carcinogenesis in different organs and systems. Despite its wide distribution pattern and physiological importance, AQP5 short-term regulation was not reported and mechanisms underlying its involvement in cancer are not well defined. In this work, we expressed rat AQP5 in yeast and investigated mechanisms of gating, as well as AQP5’s ability to facilitate H2O2 plasma membrane diffusion. We found that AQP5 can be gated by extracellular pH in a phosphorylation-dependent manner, with higher activity at physiological pH 7.4. Moreover, similar to other mammalian AQPs, AQP5 is able to increase extracellular H2O2 influx and to affect oxidative cell response with dual effects: whereas in acute oxidative stress conditions AQP5 induces an initial higher sensitivity, in chronic stress AQP5 expressing cells show improved cell survival and resistance. Our findings support the involvement of AQP5 in oxidative stress and suggest AQP5 modulation by phosphorylation as a novel tool for therapeutics.

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“…HERRMANN and MANDOL [26] concluded that pharmacological stimulation leads to a production of alkaline sweat and thermic stimulation to production of an acid sweat. But more recent observations [16] agree with those of HEUSS [27] and of MARCHIONINI [37,38]-, who found that pH is a function of sweat rate and that maximal thermal stimulation also yields an alkaline sweat.…”

Section: Phmentioning

confidence: 99%

Sweat Composition in Relation to Rate of Sweating in Patients with Cystic Fibrosis of the Pancreas

et al. 1968

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ExtractSingle sweat droplets were collected from a mineral oil-covered finger surface ( fig. 1). Rate of sweat production (sweat rate) per gland per hour was calculated. Using microtechniques, the concentrations of electrolytes and metabolites, osmolarity, pH, and viscosity were determined in undiluted pooled sweat. The following results were obtained:No significant difference was observed in sweat rate per gland between control subjects and patients with cystic fibrosis of the pancreas (CFP).Concentrations of sodium and chloride in sweat rose with increasing sweat rates in both control subjects and patients with CFP. In the patients with CFP, the lowest values were between 70 and 90 mEq/1 and the curve approached isotonicity. Chloride values were consistently lower than those of sodium. Concentrations of potassium decreased with increasing sweat rate in control subjects approaching a value of about 10 mEq/1. In patients with CFP, the values for potassium were frequently twice as high as those in the control subjects. Concentration of calcium dropped rapidly with an increasing sweat rate from 10 to 1-2 mEq/1.Concentrations of lactic acid and urea were high at low sweat rates and decreased hyperbolically with increasing rates. In patients with CFP, the values of both components were lower than those in control subjects. Urea was uniformly more concentrated in sweat than in plasma; the sweat:plasma ratio approached 1.0 with increasing sweat rates.Creatinine concentrations decreased with increasing sweat rate. No difference was observed between values in two patients and two control subjects. Glucose concentration was low (0.2-6 mg/100 ml) and was independent of the sweat rate. No significant difference was observed in comparing five patients with CFP and six control subjects.In control subjects, osmolarity decreased, with increasing sweat rate, from 240 to approximately 120 mOsmol/1 and then increased (mean 163 mOsmol/1). In patients with CFP, the curve was similar in shape but began and ended in a range of approximately 320 m/Osmol/1 (mean 299 mOsmol/1).The pH of sweat was acid at low sweat rates (pH 3.5-6.0) and was slightly alkaline (pH 7.0-8.5) at high rates. No differences were observed when comparing five patients and five control subjects.Viscosity of sweat was significantly elevated in five patients with CFP in relation to that observed in eight control subjects. This may be explained by the elevated concentration of salt in sweat of patients with CFP.The excretory pattern of urea, lactic acid, and creatinine in sweat of patients with CFP, compared with that of control subjects, argues against an increased rate of water reabsorption in the excretory ducts of the sweat gland. The course of the sodium and the chloride curve and the values of osmolarity EMRICH, STOLL, FRIOLET, COLOMBO, RIGHTERIGH, ROSSI 465 in sweat favor the assumption that in cystic fibrosis of the pancreas, the precursor fluid is in the isotonic range; net sodium reabsorption can then be calculated and appears to be defective in patients w...

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Studies of Ph of Sweat Produced by Different Forms of Stimulation*

Cited by 41 publications

References 26 publications

A Mediator‐Free Electroenzymatic Sensing Methodology to Mitigate Ionic and Electroactive Interferents' Effects for Reliable Wearable Metabolite and Nutrient Monitoring

A Mediator‐Free Electroenzymatic Sensing Methodology to Mitigate Ionic and Electroactive Interferents' Effects for Reliable Wearable Metabolite and Nutrient Monitoring

Rat Aquaporin-5 Is pH-Gated Induced by Phosphorylation and Is Implicated in Oxidative Stress

Sweat Composition in Relation to Rate of Sweating in Patients with Cystic Fibrosis of the Pancreas

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