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Kovarik JJ, Morisawa N, Wild J, Marton A, Takase‐Minegishi K, Minegishi S, Daub S, Sands JM, Klein JD, Bailey JL, Kovalik J, Rauh M, Karbach S, Hilgers KF, Luft F, Nishiyama A, Nakano D, Kitada K, Titze J. Adaptive physiological water conservation explains hypertension and muscle catabolism in experimental chronic renal failure. Acta Physiol (Oxf) 2021; 232:e13629. [PMID: 33590667 PMCID: PMC8244025 DOI: 10.1111/apha.13629] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 02/11/2021] [Accepted: 02/11/2021] [Indexed: 12/22/2022]
Abstract
Aim We have reported earlier that a high salt intake triggered an aestivation‐like natriuretic‐ureotelic body water conservation response that lowered muscle mass and increased blood pressure. Here, we tested the hypothesis that a similar adaptive water conservation response occurs in experimental chronic renal failure. Methods In four subsequent experiments in Sprague Dawley rats, we used surgical 5/6 renal mass reduction (5/6 Nx) to induce chronic renal failure. We studied solute and water excretion in 24‐hour metabolic cage experiments, chronic blood pressure by radiotelemetry, chronic metabolic adjustment in liver and skeletal muscle by metabolomics and selected enzyme activity measurements, body Na+, K+ and water by dry ashing, and acute transepidermal water loss in conjunction with skin blood flow and intra‐arterial blood pressure. Results 5/6 Nx rats were polyuric, because their kidneys could not sufficiently concentrate the urine. Physiological adaptation to this renal water loss included mobilization of nitrogen and energy from muscle for organic osmolyte production, elevated norepinephrine and copeptin levels with reduced skin blood flow, which by means of compensation reduced their transepidermal water loss. This complex physiologic‐metabolic adjustment across multiple organs allowed the rats to stabilize their body water content despite persisting renal water loss, albeit at the expense of hypertension and catabolic mobilization of muscle protein. Conclusion Physiological adaptation to body water loss, termed aestivation, is an evolutionary conserved survival strategy and an under‐studied research area in medical physiology, which besides hypertension and muscle mass loss in chronic renal failure may explain many otherwise unexplainable phenomena in medicine.
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Affiliation(s)
- Johannes J. Kovarik
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
- Clinical Division of Nephrology and Dialysis Department of Internal Medicine III Medical University of Vienna Vienna Austria
| | - Norihiko Morisawa
- Department of Pharmacology Faculty of Medicine Kagawa University Kagawa Japan
| | - Johannes Wild
- Division for Cardiology 1 Centre for Cardiology Johannes Gutenberg‐University Mainz Mainz Germany
| | - Adriana Marton
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
| | - Kaoru Takase‐Minegishi
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
- Department of Stem Cell and Immune Regulation Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Shintaro Minegishi
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
- Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Steffen Daub
- Division for Cardiology 1 Centre for Cardiology Johannes Gutenberg‐University Mainz Mainz Germany
| | - Jeff M. Sands
- Renal Division Department of Medicine Emory University Atlanta GA USA
| | - Janet D. Klein
- Renal Division Department of Medicine Emory University Atlanta GA USA
| | - James L. Bailey
- Renal Division Department of Medicine Emory University Atlanta GA USA
| | - Jean‐Paul Kovalik
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
| | - Manfred Rauh
- Division of Paediatrics Research Laboratory Erlangen Germany
| | - Susanne Karbach
- Division for Cardiology 1 Centre for Cardiology Johannes Gutenberg‐University Mainz Mainz Germany
| | - Karl F. Hilgers
- Division of Nephrology and Hypertension University Clinic Erlangen Erlangen Germany
| | - Friedrich Luft
- Experimental and Clinical Research Center Max Delbrück Center for Molecular Medicine Berlin Germany
| | - Akira Nishiyama
- Department of Pharmacology Faculty of Medicine Kagawa University Kagawa Japan
| | - Daisuke Nakano
- Department of Pharmacology Faculty of Medicine Kagawa University Kagawa Japan
| | - Kento Kitada
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
- JSPS Overseas Research Fellow Japan Society for the Promotion of Science Tokyo Japan
| | - Jens Titze
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
- Division of Nephrology and Hypertension University Clinic Erlangen Erlangen Germany
- Division of Nephrology Duke University School of Medicine Durham NC USA
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Chrit L, Bastien P, Biatry B, Simonnet JT, Potter A, Minondo AM, Flament F, Bazin R, Sockalingum GD, Leroy F, Manfait M, Hadjur C. In vitro and in vivo confocal Raman study of human skin hydration: assessment of a new moisturizing agent, pMPC. Biopolymers 2007; 85:359-69. [PMID: 17143858 DOI: 10.1002/bip.20644] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The hydration capacities of a biomimetic polymer, 2-methacryloyloxethylphosphorylcholine polymer (pMPC), alone and microencapsulated, in association with another well known hydrating polymer, Hyaluronic acid, were investigated in vitro on skin models and in vivo on volunteers by using confocal Raman microspectroscopy. The hydration impact and the relative water content in the Stratum corneum were calculated from the Raman spectra using the OH (water)/CH3 (protein) ratio. Moreover, the follow-up of the presence of pMPC through the Stratum corneum was possible with confocal Raman microspectroscopy, using a characteristic vibration of pMPC, different from that of the encapsulating material. From our in vitro measurements, the improved hydration of the Stratum corneum was confirmed by the use of the encapsulated form of pMPC, which was higher when combined with Hyaluronic acid. On the basis of these in vitro findings, we validated this trend in in vivo measurements on 26 volunteers, and found a good correlation with the in vitro results. Mechanical and ultrastructural studies have been carried out to demonstrate the positive effects of the pMPC on the Stratum corneum function, namely the interaction with lamellar lipids and the plasticizing effects, which are both supposed to spell out the moisturizing effect. This study demonstrates the efficiency of a original hydrating agent, pMPC, entrapped with Hyaluronic acid in a new type of microcapsules by the use of a novel tool developed for both in vitro and in vivo approaches. This indicates a new step to evaluate and improve new moisturizers in response to the cosmetics or dermatologic demands.
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Plasencia I, Norlén L, Bagatolli LA. Direct visualization of lipid domains in human skin stratum corneum's lipid membranes: effect of pH and temperature. Biophys J 2007; 93:3142-55. [PMID: 17631535 PMCID: PMC2025644 DOI: 10.1529/biophysj.106.096164] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The main function of skin is to serve as a physical barrier between the body and the environment. This barrier capacity is in turn a function of the physical state and structural organization of the stratum corneum extracellular lipid matrix. This lipid matrix is essentially composed of very long chain saturated ceramides, cholesterol, and free fatty acids. Three unsolved key questions are i), whether the stratum corneum extracellular lipid matrix is constituted by a single gel phase or by coexisting crystalline (solid) domains; ii), whether a separate liquid crystalline phase is present; and iii), whether pH has a direct effect on the lipid matrix phase behavior. In this work the lateral structure of membranes composed of lipids extracted from human skin stratum corneum was studied in a broad temperature range (10 degrees C-90 degrees C) using different techniques such as differential scanning calorimetry, fluorescence spectroscopy, and two-photon excitation and laser scanning confocal fluorescence microscopy. Here we show that hydrated bilayers of human skin stratum corneum lipids express a giant sponge-like morphology with dimensions corresponding to the global three-dimensional morphology of the stratum corneum extracellular space. These structures can be directly visualized using the aforementioned fluorescence microscopy techniques. At skin physiological temperatures (28 degrees C-32 degrees C), the phase state of these hydrated bilayers correspond microscopically (radial resolution limit 300 nm) to a single gel phase at pH 7, coexistence of different gel phases between pH 5 and 6, and no fluid phase at any pH. This observation suggests that the local pH in the stratum corneum may control the physical properties of the extracellular lipid matrix by regulating membrane lateral structure and stability.
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Affiliation(s)
- I Plasencia
- Membrane Biophysics and Biophotonics Group, Department of Biochemistry and Molecular Biology/MEMPHYS Center, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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Rim JE, Pinsky PM, van Osdol WW. Finite element modeling of coupled diffusion with partitioning in transdermal drug delivery. Ann Biomed Eng 2006; 33:1422-38. [PMID: 16240090 DOI: 10.1007/s10439-005-5788-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2004] [Accepted: 05/04/2004] [Indexed: 10/25/2022]
Abstract
The finite element method is employed to simulate two-dimensional (axisymmetric) drug diffusion from a finite drug reservoir into the skin. The numerical formulation is based on a general mathematical model for multicomponent nonlinear diffusion that takes into account the coupling effects between the different components. The presence of several diffusing components is crucial, as many transdermal drug delivery formulations contain one or more permeation enhancers in addition to the drug. The coupling between the drug and permeation enhancer(s) results in nonlinear diffusion with concentration-dependent diffusivities of the various components. The framework is suitable for modeling both linear and nonlinear, single- and multicomponent diffusions, however, as it reduces to the correct formulation simply by setting the relevant parameters to zero. In addition, we show that partitioning of the penetrants from the reservoir into the skin can be treated in a straightforward manner in this framework using the mixed method. Partitioning at interface boundaries poses some difficulty with the standard finite element method as it creates a discontinuity in the concentration variable at the interface. To our knowledge, nonlinear (concentration-dependent) partitioning in diffusion problems has not been treated numerically before, and we demonstrate that nonlinear partitioning may have an important role in the effect of permeation enhancers. The mixed method that we adopt includes the flux at the interface explicitly in the formulation, allowing the modeling of concentration-dependent partitioning of the permeants between the reservoir and the skin as well as constant (linear) partitioning. The result is a versatile finite element framework suitable for modeling both linear and nonlinear diffusions in heterogeneous media where the diffusivities and partition coefficients may vary in each subregion.
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Affiliation(s)
- Jee E Rim
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA.
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Ersser SJ, Getliffe K, Voegeli D, Regan S. A critical review of the inter-relationship between skin vulnerability and urinary incontinence and related nursing intervention. Int J Nurs Stud 2005; 42:823-35. [PMID: 16084927 DOI: 10.1016/j.ijnurstu.2004.12.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Revised: 12/06/2004] [Accepted: 12/09/2004] [Indexed: 11/19/2022]
Abstract
The literature reveals there has been limited critical discussion of the inter-relationship between urinary incontinence, the vulnerability of the skin and the clinical implications. This paper critically re-examines the literature to identify and apply relevant scientific principles and evidence to inform effective intervention. It includes background on the structure, function and disruption to the skin's barrier. The implications for fundamental and largely taken-for-granted nursing practices, such as washing the skin, are examined. The current state of knowledge is analysed, specifying the types of evidence available and its weaknesses, highlighting implications for a research agenda.
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Affiliation(s)
- S J Ersser
- Living with Chronic Health Needs Research Group, School of Nursing and Midwifery, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
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6
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Toskić-Radojicic M, Nonković Z. Influence of base on the release of antibiotics from officinal ointments. VOJNOSANIT PREGL 2005; 62:383-7. [PMID: 15913043 DOI: 10.2298/vsp0505383t] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Backgraund. Officinal basis for the antibiotic ointments according to the 4th Yugoslav Pharmacopoeia is a hydrophobic base containing only aliphatic hydrocarbons. The fact that antibiotics are predominantly not lipophylic raises the question about the suitability of that particular type of the base for the manufacturing of antibiotic ointments. Recent studies of the lipid analysis of the skin corneal layer indicated that lipids had shown the bilamellar organization in the skin intercorneal space. Such structural organization could be seen in the ambiphylic bases whose structure was based on carefully selected emulsifier couple, consisting of the lyotropic and thermotropic liquid crystals. The aim of this study was to test the velocity of antibiotics (klindamycin hydrochloride, erythromycin base and chloramphenicol) release from the hydrophobic ointment-type bases, and from ambiphylic bases of anionic and non-ionic types. Methods. Membrane-free agar diffusion test as the basic method for testing the release velocity in vitro and Staphylococcus aureus as the strain highly susceptible to the chosen antibiotics were used. All the analyzed samples were manufactured as the suspension-type ointments. Results. The highest growth inhibition zone of the Staphylococcus aureus strain for all three analyzed antibiotics was achieved from the non-ionogenic ambiphylic base; the clear growth inhibition zone area for Staphylococcus aureus strain in the preparations containing anionic ambiphylic base was smaller by 10-31.28%, and in the preparations containing aliphatic hydrocarbon-type base, the decrease was 11.46-31.28%, compared to the results achieved with the non-ionogenic ambiphylic base. Conclusion. The optimal release velocity for the analyzed antibiotics was achieved from the non-ionic ambiphylic base.
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Affiliation(s)
- Marija Toskić-Radojicic
- Vojnomedicinska akademija, Institut za farmaciju, Cmotravska 17, 11 040 Beograd, Srbija i Crna Gora
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7
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Backhouse L, Dias M, Gorce JP, Hadgraft J, McDonald PJ, Wiechers JW. GARField magnetic resonance profiling of the ingress of model skin-care product ingredients into human skin in vitro. J Pharm Sci 2004; 93:2274-83. [PMID: 15295788 DOI: 10.1002/jps.20137] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A preliminary study of the ingress of mineral oil, decanol, and glycerine into samples of human abdominal skin tissue in vitro made using magnetic resonance profiling with a GARField magnet is reported. Two layers, each circa 50 microm thick and attributed to stratum corneum and viable epidermis, are spatially resolved. Clear differences are observed in the magnetic resonance response of these layers arising from the application of the model skin-care product ingredients. In the case of decanol and glycerine, it is suggested that the profiles show evidence for the effects of moisturization, as distinct from hydration. In the case of glycerine, the effective ingress diffusion coefficient is calculated to be 1.3 +/- 0.5 x 10(-9) cm2s(-1).
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Affiliation(s)
- L Backhouse
- School of Electronics and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom
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8
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Toskić-Radojicić M. [Models of the lipid skin barrier]. VOJNOSANIT PREGL 2002; 59:177-82. [PMID: 12053472 DOI: 10.2298/vsp0202177t] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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9
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Chen H, Mendelsohn R, Rerek ME, Moore DJ. Effect of cholesterol on miscibility and phase behavior in binary mixtures with synthetic ceramide 2 and octadecanoic acid. Infrared studies. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1512:345-56. [PMID: 11406112 DOI: 10.1016/s0005-2736(01)00339-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The three main lipid components of the stratum corneum, namely ceramides, free fatty acids and cholesterol, play a fundamental role in the maintenance of the skin barrier. The current investigation is aimed toward understanding the miscibility and intermolecular interactions of these lipids. Toward this end, Fourier transform infrared spectroscopic studies of the three possible equimolar binary mixtures of cholesterol, a synthetic non-hydroxylated fatty acid N-acyl sphingosine with a C18 chain length (N-stearoylsphingosine, approximating human ceramide 2), and stearic acid were undertaken. The thermotropic responses of the methylene stretching and scissoring vibrations were used to evaluate chain conformation and packing respectively. Selective perdeuteration, of either the stearic acid or the ceramide acid chains, permitted separate and simultaneous evaluation of the conformational order and packing properties of the sphingosine chain, the amide linked fatty acid chains and/or the stearic acid chain. Whereas cholesterol mixed well with ceramide at physiological temperatures, the stearic acid was miscible with the cholesterol only at relatively high temperatures where the fatty acid is disordered. A complex interaction between stearic acid and ceramide was detected. A separate fatty acid-rich phase persisted until at least 50 degrees C, whereas at higher temperatures the components appear to be quite miscible. However, a preferential association of the fatty acid with the ceramide base chain is indicated. None of the binary systems studied exhibit miscibility and interactions resembling those in the ternary mixtures of these substances, which is widely used to model stratum corneum. The role of cholesterol in controlling the miscibility characteristics in the ternary system is evident.
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Affiliation(s)
- H Chen
- Rutgers University, Department of Chemistry, Newark, NJ 07102, USA
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10
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Chen H, Mendelsohn R, Rerek ME, Moore DJ. Fourier transform infrared spectroscopy and differential scanning calorimetry studies of fatty acid homogeneous ceramide 2. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1468:293-303. [PMID: 11018673 DOI: 10.1016/s0005-2736(00)00271-6] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Ceramides provide a major component of the barrier function of skin. An understanding of barrier organization requires a detailed characterization of ceramide phase behavior and molecular interactions. Toward this end, Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC) studies of ceramide 2 analogues (non-hydroxylated fatty acid N-acyl sphingosines) of specific chain lengths (C(14), C(16), C(18), C(20)) are presented. In addition, the molecular interactions of the individual chains in each molecule are elucidated through thermotropic FTIR studies of derivatives possessing perdeuterated fatty acid chains. DSC data showed a much smaller chain length variation (for the C(16), C(18), C(20) derivatives) in the main order-disorder transition temperature (approx. 93+/-1 degrees C) than is observed in the corresponding series of phosphatidylcholines, consistent with minimal ceramide hydration. The temperature dependence of the methylene stretching and scissoring modes revealed a solid-solid phase transition at 20-25 degrees C below the main order-disorder transition accompanied by chain packing alterations from orthorhombic-->hexagonal subcells. The chain packing transition was accompanied by enhanced penetration of water into the polar region. This was deduced from the temperature dependence of the amide I and II modes, which provide direct evidence for H-->D exchange. The CD(2) scissoring mode splitting of the deuterated fatty acid constituent of the C(16), C(18), C(20) chains revealed preferential segregation of microdomains (3-5 chains) of this species within the orthorhombic phase. In contrast, the sphingosine base chains appeared to be sufficiently separated so as to inhibit interchain vibrational coupling between them. FTIR spectroscopy provides a convenient means for characterizing domain formation, chain packing, and hydration sites of these phases, which are highly ordered under physiological conditions.
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Affiliation(s)
- H Chen
- Rutgers University, Department of Chemistry, 73 Warren Street, Newark, NJ 07102, USA
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11
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Krien PM, Kermici M. Evidence for the existence of a self-regulated enzymatic process within the human stratum corneum -an unexpected role for urocanic acid. J Invest Dermatol 2000; 115:414-20. [PMID: 10951277 DOI: 10.1046/j.1523-1747.2000.00083.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The existence of a flux of proton donors from skin (inner part of the forearm) to the electrode was observed in 12 male and female volunteers. This flux was used to collect and identify the ionic species responsible for skin acidity. It was then found that: (i) pK of these proton donors (pK = 6.13 +/- 0.07) was quasi-identical to that of trans-urocanic acid (6.10), and (ii) the amount of urocanic acid present in stratum corneum was sufficient in itself to explain the acidic level as measured with pH meter (R = 0.8484, n = 10, p = 0.00136). As a result, the contribution of other ionic species can be considered as negligible in normal human skin. The data recorded led us to identify three groups (Fast, Medium, and Slow) characterized by different skin surface pH values (low, medium, and close to neutral) and showing a pH gradient in the outer layers of the stratum corneum, or not. Data analysis suggests that these characteristics depend on urocanic acid production rate within the stratum corneum and that this production rate is self-regulated by its urocanic acid content.
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Affiliation(s)
- P M Krien
- L'Oréal-Advanced Research-Life Sciences Research, Clichy Cedex, France.
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12
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Ollmar S. Methods of information extraction from impedance spectra of biological tissue, in particular skin and oral mucosa—a critical review and suggestions for the future. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0302-4598(98)00082-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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13
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Moore DJ, Rerek ME, Mendelsohn R. FTIR Spectroscopy Studies of the Conformational Order and Phase Behavior of Ceramides. J Phys Chem B 1997. [DOI: 10.1021/jp9718109] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Forslind B, Engström S, Engblom J, Norlén L. A novel approach to the understanding of human skin barrier function. J Dermatol Sci 1997; 14:115-25. [PMID: 9039975 DOI: 10.1016/s0923-1811(96)00559-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The basis for externally caused skin disorders is penetration of the skin barrier. A recent model for the skin barrier, the domain mosaic model, based on current knowledge of the physics of lipid bilayer organization gave tentative explanations for several aspects of function. It is demonstrated here that a development of the model explains how the requirements are met for a water-tight structure that will still allow a controlled, minute loss of water, the perspiratio insensibilis, necessary for maintaining plasticity of the keratin. A major advantage of the extended model is that it allows an interpretation of the changes imposed on the structure when in contact with detergents and/or penetration enhancers.
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Affiliation(s)
- B Forslind
- EDRG, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
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